diff --git a/packages/react-devtools-shared/src/__tests__/FastRefreshDevToolsIntegration-test.js b/packages/react-devtools-shared/src/__tests__/FastRefreshDevToolsIntegration-test.js
index 279390c5fca8bd..4e2cdecfb9e678 100644
--- a/packages/react-devtools-shared/src/__tests__/FastRefreshDevToolsIntegration-test.js
+++ b/packages/react-devtools-shared/src/__tests__/FastRefreshDevToolsIntegration-test.js
@@ -131,25 +131,48 @@ describe('Fast Refresh', () => {
       };
 
       function Child() {
-        return null;
+        return <div />;
       };
 
       export default Parent;
     `);
+    expect(store).toMatchInlineSnapshot(`
+      [root]
+        ▾ <Parent>
+            <Child key="A">
+    `);
+
+    let element = container.firstChild;
+    expect(container.firstChild).not.toBe(null);
+
+    patch(`
+      function Parent() {
+        return <Child key="A" />;
+      };
+
+      function Child() {
+        return <div />;
+      };
 
+      export default Parent;
+    `);
     expect(store).toMatchInlineSnapshot(`
       [root]
         ▾ <Parent>
             <Child key="A">
     `);
 
+    // State is preserved; this verifies that Fast Refresh is wired up.
+    expect(container.firstChild).toBe(element);
+    element = container.firstChild;
+
     patch(`
       function Parent() {
         return <Child key="B" />;
       };
 
       function Child() {
-        return null;
+        return <div />;
       };
 
       export default Parent;
@@ -159,6 +182,9 @@ describe('Fast Refresh', () => {
         ▾ <Parent>
             <Child key="B">
     `);
+
+    // State is reset because hooks changed.
+    expect(container.firstChild).not.toBe(element);
   });
 
   it('should not break when there are warnings in between patching', () => {
@@ -168,10 +194,8 @@ describe('Fast Refresh', () => {
 
       export default function Component() {
         const [state, setState] = useState(1);
-
         console.warn("Expected warning during render");
-
-        return <div />;
+        return null;
       }
     `);
     });
@@ -181,56 +205,56 @@ describe('Fast Refresh', () => {
           <Component> ⚠
     `);
 
-    let element = container.firstChild;
-
     withErrorsOrWarningsIgnored(['Expected warning during render'], () => {
       patch(`
-      const {useState} = React;
+      const {useEffect, useState} = React;
 
       export default function Component() {
         const [state, setState] = useState(1);
-
         console.warn("Expected warning during render");
-
-        return <div id="one" />;
+        return null;
       }
     `);
     });
-
-    // This is the same component type, so the warning count carries over.
     expect(store).toMatchInlineSnapshot(`
       ✕ 0, ⚠ 2
       [root]
           <Component> ⚠
     `);
 
-    // State is preserved; this verifies that Fast Refresh is wired up.
-    expect(container.firstChild).toBe(element);
-    element = container.firstChild;
-
     withErrorsOrWarningsIgnored(['Expected warning during render'], () => {
       patch(`
       const {useEffect, useState} = React;
 
       export default function Component() {
-        const [state, setState] = useState(3);
+        const [state, setState] = useState(1);
         useEffect(() => {});
-
         console.warn("Expected warning during render");
-
-        return <div id="one" />;
+        return null;
       }
     `);
     });
-
-    // This is a new component type, so the warning count has been reset.
     expect(store).toMatchInlineSnapshot(`
       ✕ 0, ⚠ 1
       [root]
           <Component> ⚠
     `);
 
-    // State is reset because hooks changed.
-    expect(container.firstChild).not.toBe(element);
+    withErrorsOrWarningsIgnored(['Expected warning during render'], () => {
+      patch(`
+      const {useEffect, useState} = React;
+
+      export default function Component() {
+        const [state, setState] = useState(1);
+        console.warn("Expected warning during render");
+        return null;
+      }
+    `);
+    });
+    expect(store).toMatchInlineSnapshot(`
+      ✕ 0, ⚠ 1
+      [root]
+          <Component> ⚠
+    `);
   });
 });
diff --git a/packages/react-devtools-shared/src/__tests__/__snapshots__/profilingCache-test.js.snap b/packages/react-devtools-shared/src/__tests__/__snapshots__/profilingCache-test.js.snap
index ad1d487ea790cd..8f07adaaf4daeb 100644
--- a/packages/react-devtools-shared/src/__tests__/__snapshots__/profilingCache-test.js.snap
+++ b/packages/react-devtools-shared/src/__tests__/__snapshots__/profilingCache-test.js.snap
@@ -10,14 +10,14 @@ Object {
       "props": null,
       "state": null,
     },
-    3 => Object {
+    4 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": true,
       "props": null,
       "state": null,
     },
-    5 => Object {
+    6 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": true,
@@ -30,14 +30,14 @@ Object {
   "fiberActualDurations": Map {
     1 => 16,
     2 => 16,
-    3 => 1,
-    5 => 1,
+    4 => 1,
+    6 => 1,
   },
   "fiberSelfDurations": Map {
     1 => 0,
     2 => 10,
-    3 => 1,
-    5 => 1,
+    4 => 1,
+    6 => 1,
   },
   "passiveEffectDuration": null,
   "priorityLevel": "Normal",
@@ -104,7 +104,7 @@ Object {
 exports[`ProfilingCache should calculate self duration correctly for suspended views: CommitDetails with filtered self durations 2`] = `
 Object {
   "changeDescriptions": Map {
-    5 => Object {
+    7 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": true,
@@ -115,11 +115,11 @@ Object {
   "duration": 3,
   "effectDuration": null,
   "fiberActualDurations": Map {
-    5 => 3,
+    7 => 3,
     3 => 3,
   },
   "fiberSelfDurations": Map {
-    5 => 3,
+    7 => 3,
     3 => 0,
   },
   "passiveEffectDuration": null,
@@ -147,21 +147,21 @@ Object {
       "props": null,
       "state": null,
     },
-    3 => Object {
+    4 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": true,
       "props": null,
       "state": null,
     },
-    4 => Object {
+    5 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": true,
       "props": null,
       "state": null,
     },
-    5 => Object {
+    6 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": true,
@@ -174,16 +174,16 @@ Object {
   "fiberActualDurations": Map {
     1 => 12,
     2 => 12,
-    3 => 0,
-    4 => 1,
+    4 => 0,
     5 => 1,
+    6 => 1,
   },
   "fiberSelfDurations": Map {
     1 => 0,
     2 => 10,
-    3 => 0,
-    4 => 1,
+    4 => 0,
     5 => 1,
+    6 => 1,
   },
   "passiveEffectDuration": null,
   "priorityLevel": "Normal",
@@ -203,21 +203,21 @@ Object {
 exports[`ProfilingCache should collect data for each commit: CommitDetails commitIndex: 1 1`] = `
 Object {
   "changeDescriptions": Map {
-    3 => Object {
+    4 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": false,
       "props": Array [],
       "state": null,
     },
-    4 => Object {
+    5 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": false,
       "props": Array [],
       "state": null,
     },
-    6 => Object {
+    7 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": true,
@@ -237,16 +237,16 @@ Object {
   "duration": 13,
   "effectDuration": null,
   "fiberActualDurations": Map {
-    3 => 0,
-    4 => 1,
-    6 => 2,
+    4 => 0,
+    5 => 1,
+    7 => 2,
     2 => 13,
     1 => 13,
   },
   "fiberSelfDurations": Map {
-    3 => 0,
-    4 => 1,
-    6 => 2,
+    4 => 0,
+    5 => 1,
+    7 => 2,
     2 => 10,
     1 => 0,
   },
@@ -268,7 +268,7 @@ Object {
 exports[`ProfilingCache should collect data for each commit: CommitDetails commitIndex: 2 1`] = `
 Object {
   "changeDescriptions": Map {
-    3 => Object {
+    4 => Object {
       "context": null,
       "didHooksChange": false,
       "isFirstMount": false,
@@ -288,12 +288,12 @@ Object {
   "duration": 10,
   "effectDuration": null,
   "fiberActualDurations": Map {
-    3 => 0,
+    4 => 0,
     2 => 10,
     1 => 10,
   },
   "fiberSelfDurations": Map {
-    3 => 0,
+    4 => 0,
     2 => 10,
     1 => 0,
   },
@@ -368,7 +368,7 @@ Object {
               },
             ],
             Array [
-              3,
+              4,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -378,7 +378,7 @@ Object {
               },
             ],
             Array [
-              4,
+              5,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -388,7 +388,7 @@ Object {
               },
             ],
             Array [
-              5,
+              6,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -410,15 +410,15 @@ Object {
               12,
             ],
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              4,
+              5,
               1,
             ],
             Array [
-              5,
+              6,
               1,
             ],
           ],
@@ -432,15 +432,15 @@ Object {
               10,
             ],
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              4,
+              5,
               1,
             ],
             Array [
-              5,
+              6,
               1,
             ],
           ],
@@ -460,7 +460,7 @@ Object {
         Object {
           "changeDescriptions": Array [
             Array [
-              3,
+              4,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -470,7 +470,7 @@ Object {
               },
             ],
             Array [
-              4,
+              5,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -480,7 +480,7 @@ Object {
               },
             ],
             Array [
-              6,
+              7,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -506,15 +506,15 @@ Object {
           "effectDuration": null,
           "fiberActualDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              4,
+              5,
               1,
             ],
             Array [
-              6,
+              7,
               2,
             ],
             Array [
@@ -528,15 +528,15 @@ Object {
           ],
           "fiberSelfDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              4,
+              5,
               1,
             ],
             Array [
-              6,
+              7,
               2,
             ],
             Array [
@@ -564,7 +564,7 @@ Object {
         Object {
           "changeDescriptions": Array [
             Array [
-              3,
+              4,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -590,7 +590,7 @@ Object {
           "effectDuration": null,
           "fiberActualDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
@@ -604,7 +604,7 @@ Object {
           ],
           "fiberSelfDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
@@ -723,34 +723,34 @@ Object {
           2,
           12000,
           1,
-          3,
+          4,
           5,
           2,
           2,
           2,
           3,
           4,
-          3,
+          4,
           0,
           1,
-          4,
+          5,
           5,
           2,
           2,
           2,
           4,
           4,
-          4,
+          5,
           1000,
           1,
-          5,
+          6,
           8,
           2,
           2,
           2,
           0,
           4,
-          5,
+          6,
           1000,
         ],
         Array [
@@ -766,14 +766,14 @@ Object {
           1,
           50,
           1,
-          6,
+          7,
           5,
           2,
           2,
           1,
           2,
           4,
-          6,
+          7,
           2000,
           4,
           2,
@@ -781,10 +781,10 @@ Object {
           3,
           2,
           4,
-          3,
           4,
-          6,
           5,
+          7,
+          6,
           4,
           1,
           14000,
@@ -795,16 +795,16 @@ Object {
           0,
           2,
           2,
-          6,
-          4,
+          7,
+          5,
           4,
           2,
           11000,
           3,
           2,
           2,
-          3,
-          5,
+          4,
+          6,
           4,
           1,
           11000,
@@ -815,7 +815,7 @@ Object {
           0,
           2,
           1,
-          3,
+          4,
         ],
       ],
       "rootID": 1,
@@ -834,7 +834,7 @@ Array [
 ]
 `;
 
-exports[`ProfilingCache should collect data for each rendered fiber: FiberCommits: element 3 1`] = `
+exports[`ProfilingCache should collect data for each rendered fiber: FiberCommits: element 4 1`] = `
 Array [
   0,
   1,
@@ -842,20 +842,20 @@ Array [
 ]
 `;
 
-exports[`ProfilingCache should collect data for each rendered fiber: FiberCommits: element 4 1`] = `
+exports[`ProfilingCache should collect data for each rendered fiber: FiberCommits: element 5 1`] = `
 Array [
   0,
 ]
 `;
 
-exports[`ProfilingCache should collect data for each rendered fiber: FiberCommits: element 5 1`] = `
+exports[`ProfilingCache should collect data for each rendered fiber: FiberCommits: element 6 1`] = `
 Array [
   1,
   2,
 ]
 `;
 
-exports[`ProfilingCache should collect data for each rendered fiber: FiberCommits: element 6 1`] = `
+exports[`ProfilingCache should collect data for each rendered fiber: FiberCommits: element 7 1`] = `
 Array [
   2,
 ]
@@ -879,7 +879,7 @@ Object {
               },
             ],
             Array [
-              3,
+              4,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -889,7 +889,7 @@ Object {
               },
             ],
             Array [
-              4,
+              5,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -911,11 +911,11 @@ Object {
               11,
             ],
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              4,
+              5,
               1,
             ],
           ],
@@ -929,11 +929,11 @@ Object {
               10,
             ],
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              4,
+              5,
               1,
             ],
           ],
@@ -953,7 +953,7 @@ Object {
         Object {
           "changeDescriptions": Array [
             Array [
-              3,
+              4,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -963,7 +963,7 @@ Object {
               },
             ],
             Array [
-              5,
+              6,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -989,11 +989,11 @@ Object {
           "effectDuration": null,
           "fiberActualDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              5,
+              6,
               1,
             ],
             Array [
@@ -1007,11 +1007,11 @@ Object {
           ],
           "fiberSelfDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              5,
+              6,
               1,
             ],
             Array [
@@ -1039,7 +1039,7 @@ Object {
         Object {
           "changeDescriptions": Array [
             Array [
-              3,
+              4,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -1049,7 +1049,7 @@ Object {
               },
             ],
             Array [
-              5,
+              6,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -1059,7 +1059,7 @@ Object {
               },
             ],
             Array [
-              6,
+              7,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -1085,15 +1085,15 @@ Object {
           "effectDuration": null,
           "fiberActualDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              5,
+              6,
               1,
             ],
             Array [
-              6,
+              7,
               2,
             ],
             Array [
@@ -1107,15 +1107,15 @@ Object {
           ],
           "fiberSelfDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              5,
+              6,
               1,
             ],
             Array [
-              6,
+              7,
               2,
             ],
             Array [
@@ -1182,24 +1182,24 @@ Object {
           2,
           11000,
           1,
-          3,
+          4,
           5,
           2,
           2,
           2,
           3,
           4,
-          3,
+          4,
           0,
           1,
-          4,
+          5,
           8,
           2,
           2,
           2,
           0,
           4,
-          4,
+          5,
           1000,
         ],
         Array [
@@ -1215,14 +1215,14 @@ Object {
           1,
           49,
           1,
-          5,
+          6,
           5,
           2,
           2,
           1,
           2,
           4,
-          5,
+          6,
           1000,
           4,
           2,
@@ -1230,9 +1230,9 @@ Object {
           3,
           2,
           3,
-          3,
-          5,
           4,
+          6,
+          5,
           4,
           1,
           12000,
@@ -1250,14 +1250,14 @@ Object {
           1,
           50,
           1,
-          6,
+          7,
           5,
           2,
           2,
           1,
           2,
           4,
-          6,
+          7,
           2000,
           4,
           2,
@@ -1265,10 +1265,10 @@ Object {
           3,
           2,
           4,
-          3,
-          5,
-          6,
           4,
+          6,
+          7,
+          5,
           4,
           1,
           14000,
@@ -1287,21 +1287,21 @@ Object {
   "commitData": Array [
     Object {
       "changeDescriptions": Map {
-        3 => Object {
+        4 => Object {
           "context": null,
           "didHooksChange": false,
           "isFirstMount": false,
           "props": Array [],
           "state": null,
         },
-        4 => Object {
+        5 => Object {
           "context": null,
           "didHooksChange": false,
           "isFirstMount": false,
           "props": Array [],
           "state": null,
         },
-        10 => Object {
+        12 => Object {
           "context": null,
           "didHooksChange": false,
           "isFirstMount": true,
@@ -1321,16 +1321,16 @@ Object {
       "duration": 13,
       "effectDuration": null,
       "fiberActualDurations": Map {
-        3 => 0,
-        4 => 1,
-        10 => 2,
+        4 => 0,
+        5 => 1,
+        12 => 2,
         2 => 13,
         1 => 13,
       },
       "fiberSelfDurations": Map {
-        3 => 0,
-        4 => 1,
-        10 => 2,
+        4 => 0,
+        5 => 1,
+        12 => 2,
         2 => 10,
         1 => 0,
       },
@@ -1349,7 +1349,7 @@ Object {
     },
     Object {
       "changeDescriptions": Map {
-        3 => Object {
+        4 => Object {
           "context": null,
           "didHooksChange": false,
           "isFirstMount": false,
@@ -1369,12 +1369,12 @@ Object {
       "duration": 10,
       "effectDuration": null,
       "fiberActualDurations": Map {
-        3 => 0,
+        4 => 0,
         2 => 10,
         1 => 10,
       },
       "fiberSelfDurations": Map {
-        3 => 0,
+        4 => 0,
         2 => 10,
         1 => 0,
       },
@@ -1431,9 +1431,9 @@ Object {
   "initialTreeBaseDurations": Map {
     1 => 12,
     2 => 12,
-    3 => 0,
-    4 => 1,
+    4 => 0,
     5 => 1,
+    6 => 1,
   },
   "operations": Array [
     Array [
@@ -1449,14 +1449,14 @@ Object {
       1,
       50,
       1,
-      10,
+      12,
       5,
       2,
       2,
       1,
       2,
       4,
-      10,
+      12,
       2000,
       4,
       2,
@@ -1464,10 +1464,10 @@ Object {
       3,
       2,
       4,
-      3,
       4,
-      10,
       5,
+      12,
+      6,
       4,
       1,
       14000,
@@ -1478,16 +1478,16 @@ Object {
       0,
       2,
       2,
-      10,
-      4,
+      12,
+      5,
       4,
       2,
       11000,
       3,
       2,
       2,
-      3,
-      5,
+      4,
+      6,
       4,
       1,
       11000,
@@ -1498,7 +1498,7 @@ Object {
       0,
       2,
       1,
-      3,
+      4,
     ],
   ],
   "rootID": 1,
@@ -1515,9 +1515,9 @@ Object {
     },
     2 => Object {
       "children": Array [
-        3,
         4,
         5,
+        6,
       ],
       "displayName": "Parent",
       "hocDisplayNames": null,
@@ -1525,29 +1525,29 @@ Object {
       "key": null,
       "type": 5,
     },
-    3 => Object {
+    4 => Object {
       "children": Array [],
       "displayName": "Child",
       "hocDisplayNames": null,
-      "id": 3,
+      "id": 4,
       "key": "0",
       "type": 5,
     },
-    4 => Object {
+    5 => Object {
       "children": Array [],
       "displayName": "Child",
       "hocDisplayNames": null,
-      "id": 4,
+      "id": 5,
       "key": "1",
       "type": 5,
     },
-    5 => Object {
+    6 => Object {
       "children": Array [],
       "displayName": "Child",
       "hocDisplayNames": Array [
         "Memo",
       ],
-      "id": 5,
+      "id": 6,
       "key": null,
       "type": 8,
     },
@@ -1560,21 +1560,21 @@ Object {
   "commitData": Array [
     Object {
       "changeDescriptions": Map {
-        12 => Object {
+        14 => Object {
           "context": null,
           "didHooksChange": false,
           "isFirstMount": true,
           "props": null,
           "state": null,
         },
-        13 => Object {
+        16 => Object {
           "context": null,
           "didHooksChange": false,
           "isFirstMount": true,
           "props": null,
           "state": null,
         },
-        14 => Object {
+        17 => Object {
           "context": null,
           "didHooksChange": false,
           "isFirstMount": true,
@@ -1585,16 +1585,16 @@ Object {
       "duration": 11,
       "effectDuration": null,
       "fiberActualDurations": Map {
-        11 => 11,
-        12 => 11,
-        13 => 0,
-        14 => 1,
+        13 => 11,
+        14 => 11,
+        16 => 0,
+        17 => 1,
       },
       "fiberSelfDurations": Map {
-        11 => 0,
-        12 => 10,
         13 => 0,
-        14 => 1,
+        14 => 10,
+        16 => 0,
+        17 => 1,
       },
       "passiveEffectDuration": null,
       "priorityLevel": "Normal",
@@ -1603,7 +1603,7 @@ Object {
         Object {
           "displayName": "Anonymous",
           "hocDisplayNames": null,
-          "id": 11,
+          "id": 13,
           "key": null,
           "type": 11,
         },
@@ -1615,7 +1615,7 @@ Object {
   "operations": Array [
     Array [
       1,
-      11,
+      13,
       15,
       6,
       80,
@@ -1633,46 +1633,46 @@ Object {
       1,
       48,
       1,
-      11,
+      13,
       11,
       1,
       1,
       4,
-      11,
+      13,
       11000,
       1,
-      12,
+      14,
       5,
-      11,
+      13,
       0,
       1,
       0,
       4,
-      12,
+      14,
       11000,
       1,
-      13,
+      16,
       5,
-      12,
-      12,
+      14,
+      14,
       2,
       3,
       4,
-      13,
+      16,
       0,
       1,
-      14,
+      17,
       8,
-      12,
-      12,
+      14,
+      14,
       2,
       0,
       4,
-      14,
+      17,
       1000,
     ],
   ],
-  "rootID": 11,
+  "rootID": 13,
   "snapshots": Map {},
 }
 `;
@@ -1693,7 +1693,7 @@ Object {
         Object {
           "displayName": "Anonymous",
           "hocDisplayNames": null,
-          "id": 6,
+          "id": 7,
           "key": null,
           "type": 11,
         },
@@ -1702,62 +1702,62 @@ Object {
   ],
   "displayName": "Parent",
   "initialTreeBaseDurations": Map {
-    6 => 11,
     7 => 11,
-    8 => 0,
-    9 => 1,
+    8 => 11,
+    10 => 0,
+    11 => 1,
   },
   "operations": Array [
     Array [
       1,
-      6,
+      7,
       0,
       2,
       4,
-      9,
+      11,
+      10,
       8,
       7,
-      6,
     ],
   ],
-  "rootID": 6,
+  "rootID": 7,
   "snapshots": Map {
-    6 => Object {
+    7 => Object {
       "children": Array [
-        7,
+        8,
       ],
       "displayName": null,
       "hocDisplayNames": null,
-      "id": 6,
+      "id": 7,
       "key": null,
       "type": 11,
     },
-    7 => Object {
+    8 => Object {
       "children": Array [
-        8,
-        9,
+        10,
+        11,
       ],
       "displayName": "Parent",
       "hocDisplayNames": null,
-      "id": 7,
+      "id": 8,
       "key": null,
       "type": 5,
     },
-    8 => Object {
+    10 => Object {
       "children": Array [],
       "displayName": "Child",
       "hocDisplayNames": null,
-      "id": 8,
+      "id": 10,
       "key": "0",
       "type": 5,
     },
-    9 => Object {
+    11 => Object {
       "children": Array [],
       "displayName": "Child",
       "hocDisplayNames": Array [
         "Memo",
       ],
-      "id": 9,
+      "id": 11,
       "key": null,
       "type": 8,
     },
@@ -1773,7 +1773,7 @@ Object {
         Object {
           "changeDescriptions": Array [
             Array [
-              3,
+              4,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -1783,7 +1783,7 @@ Object {
               },
             ],
             Array [
-              4,
+              5,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -1793,7 +1793,7 @@ Object {
               },
             ],
             Array [
-              10,
+              12,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -1819,15 +1819,15 @@ Object {
           "effectDuration": null,
           "fiberActualDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              4,
+              5,
               1,
             ],
             Array [
-              10,
+              12,
               2,
             ],
             Array [
@@ -1841,15 +1841,15 @@ Object {
           ],
           "fiberSelfDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
-              4,
+              5,
               1,
             ],
             Array [
-              10,
+              12,
               2,
             ],
             Array [
@@ -1877,7 +1877,7 @@ Object {
         Object {
           "changeDescriptions": Array [
             Array [
-              3,
+              4,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -1903,7 +1903,7 @@ Object {
           "effectDuration": null,
           "fiberActualDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
@@ -1917,7 +1917,7 @@ Object {
           ],
           "fiberSelfDurations": Array [
             Array [
-              3,
+              4,
               0,
             ],
             Array [
@@ -2004,15 +2004,15 @@ Object {
           12,
         ],
         Array [
-          3,
+          4,
           0,
         ],
         Array [
-          4,
+          5,
           1,
         ],
         Array [
-          5,
+          6,
           1,
         ],
       ],
@@ -2030,14 +2030,14 @@ Object {
           1,
           50,
           1,
-          10,
+          12,
           5,
           2,
           2,
           1,
           2,
           4,
-          10,
+          12,
           2000,
           4,
           2,
@@ -2045,10 +2045,10 @@ Object {
           3,
           2,
           4,
-          3,
           4,
-          10,
           5,
+          12,
+          6,
           4,
           1,
           14000,
@@ -2059,16 +2059,16 @@ Object {
           0,
           2,
           2,
-          10,
-          4,
+          12,
+          5,
           4,
           2,
           11000,
           3,
           2,
           2,
-          3,
-          5,
+          4,
+          6,
           4,
           1,
           11000,
@@ -2079,7 +2079,7 @@ Object {
           0,
           2,
           1,
-          3,
+          4,
         ],
       ],
       "rootID": 1,
@@ -2101,9 +2101,9 @@ Object {
           2,
           Object {
             "children": Array [
-              3,
               4,
               5,
+              6,
             ],
             "displayName": "Parent",
             "hocDisplayNames": null,
@@ -2113,36 +2113,36 @@ Object {
           },
         ],
         Array [
-          3,
+          4,
           Object {
             "children": Array [],
             "displayName": "Child",
             "hocDisplayNames": null,
-            "id": 3,
+            "id": 4,
             "key": "0",
             "type": 5,
           },
         ],
         Array [
-          4,
+          5,
           Object {
             "children": Array [],
             "displayName": "Child",
             "hocDisplayNames": null,
-            "id": 4,
+            "id": 5,
             "key": "1",
             "type": 5,
           },
         ],
         Array [
-          5,
+          6,
           Object {
             "children": Array [],
             "displayName": "Child",
             "hocDisplayNames": Array [
               "Memo",
             ],
-            "id": 5,
+            "id": 6,
             "key": null,
             "type": 8,
           },
@@ -2154,7 +2154,7 @@ Object {
         Object {
           "changeDescriptions": Array [
             Array [
-              12,
+              14,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -2164,7 +2164,7 @@ Object {
               },
             ],
             Array [
-              13,
+              16,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -2174,7 +2174,7 @@ Object {
               },
             ],
             Array [
-              14,
+              17,
               Object {
                 "context": null,
                 "didHooksChange": false,
@@ -2188,37 +2188,37 @@ Object {
           "effectDuration": null,
           "fiberActualDurations": Array [
             Array [
-              11,
+              13,
               11,
             ],
             Array [
-              12,
+              14,
               11,
             ],
             Array [
-              13,
+              16,
               0,
             ],
             Array [
-              14,
+              17,
               1,
             ],
           ],
           "fiberSelfDurations": Array [
             Array [
-              11,
+              13,
               0,
             ],
             Array [
-              12,
+              14,
               10,
             ],
             Array [
-              13,
+              16,
               0,
             ],
             Array [
-              14,
+              17,
               1,
             ],
           ],
@@ -2229,7 +2229,7 @@ Object {
             Object {
               "displayName": "Anonymous",
               "hocDisplayNames": null,
-              "id": 11,
+              "id": 13,
               "key": null,
               "type": 11,
             },
@@ -2241,7 +2241,7 @@ Object {
       "operations": Array [
         Array [
           1,
-          11,
+          13,
           15,
           6,
           80,
@@ -2259,46 +2259,46 @@ Object {
           1,
           48,
           1,
-          11,
+          13,
           11,
           1,
           1,
           4,
-          11,
+          13,
           11000,
           1,
-          12,
+          14,
           5,
-          11,
+          13,
           0,
           1,
           0,
           4,
-          12,
+          14,
           11000,
           1,
-          13,
+          16,
           5,
-          12,
-          12,
+          14,
+          14,
           2,
           3,
           4,
-          13,
+          16,
           0,
           1,
-          14,
+          17,
           8,
-          12,
-          12,
+          14,
+          14,
           2,
           0,
           4,
-          14,
+          17,
           1000,
         ],
       ],
-      "rootID": 11,
+      "rootID": 13,
       "snapshots": Array [],
     },
     Object {
@@ -2316,7 +2316,7 @@ Object {
             Object {
               "displayName": "Anonymous",
               "hocDisplayNames": null,
-              "id": 6,
+              "id": 7,
               "key": null,
               "type": 11,
             },
@@ -2326,84 +2326,84 @@ Object {
       "displayName": "Parent",
       "initialTreeBaseDurations": Array [
         Array [
-          6,
+          7,
           11,
         ],
         Array [
-          7,
+          8,
           11,
         ],
         Array [
-          8,
+          10,
           0,
         ],
         Array [
-          9,
+          11,
           1,
         ],
       ],
       "operations": Array [
         Array [
           1,
-          6,
+          7,
           0,
           2,
           4,
-          9,
+          11,
+          10,
           8,
           7,
-          6,
         ],
       ],
-      "rootID": 6,
+      "rootID": 7,
       "snapshots": Array [
         Array [
-          6,
+          7,
           Object {
             "children": Array [
-              7,
+              8,
             ],
             "displayName": null,
             "hocDisplayNames": null,
-            "id": 6,
+            "id": 7,
             "key": null,
             "type": 11,
           },
         ],
         Array [
-          7,
+          8,
           Object {
             "children": Array [
-              8,
-              9,
+              10,
+              11,
             ],
             "displayName": "Parent",
             "hocDisplayNames": null,
-            "id": 7,
+            "id": 8,
             "key": null,
             "type": 5,
           },
         ],
         Array [
-          8,
+          10,
           Object {
             "children": Array [],
             "displayName": "Child",
             "hocDisplayNames": null,
-            "id": 8,
+            "id": 10,
             "key": "0",
             "type": 5,
           },
         ],
         Array [
-          9,
+          11,
           Object {
             "children": Array [],
             "displayName": "Child",
             "hocDisplayNames": Array [
               "Memo",
             ],
-            "id": 9,
+            "id": 11,
             "key": null,
             "type": 8,
           },
diff --git a/packages/react-devtools-shared/src/__tests__/__snapshots__/profilingCommitTreeBuilder-test.js.snap b/packages/react-devtools-shared/src/__tests__/__snapshots__/profilingCommitTreeBuilder-test.js.snap
index 1fa419013d98f4..43f3f91c7a24f4 100644
--- a/packages/react-devtools-shared/src/__tests__/__snapshots__/profilingCommitTreeBuilder-test.js.snap
+++ b/packages/react-devtools-shared/src/__tests__/__snapshots__/profilingCommitTreeBuilder-test.js.snap
@@ -71,7 +71,7 @@ Object {
     },
     3 => Object {
       "children": Array [
-        4,
+        6,
       ],
       "displayName": "Suspense",
       "hocDisplayNames": null,
@@ -81,11 +81,11 @@ Object {
       "treeBaseDuration": 0,
       "type": 12,
     },
-    4 => Object {
+    6 => Object {
       "children": Array [],
       "displayName": "LazyInnerComponent",
       "hocDisplayNames": null,
-      "id": 4,
+      "id": 6,
       "key": null,
       "parentID": 3,
       "treeBaseDuration": 0,
@@ -167,7 +167,7 @@ Object {
     },
     3 => Object {
       "children": Array [
-        4,
+        6,
       ],
       "displayName": "Suspense",
       "hocDisplayNames": null,
@@ -177,11 +177,11 @@ Object {
       "treeBaseDuration": 0,
       "type": 12,
     },
-    4 => Object {
+    6 => Object {
       "children": Array [],
       "displayName": "LazyInnerComponent",
       "hocDisplayNames": null,
-      "id": 4,
+      "id": 6,
       "key": null,
       "parentID": 3,
       "treeBaseDuration": 0,
diff --git a/packages/react-devtools-shared/src/__tests__/setupTests.js b/packages/react-devtools-shared/src/__tests__/setupTests.js
index b244c7e0cf17e7..811f5661dc1350 100644
--- a/packages/react-devtools-shared/src/__tests__/setupTests.js
+++ b/packages/react-devtools-shared/src/__tests__/setupTests.js
@@ -12,8 +12,47 @@ import type {
   FrontendBridge,
 } from 'react-devtools-shared/src/bridge';
 
+import {Console} from 'console';
+
+// Override Jest's default behavior of prepending location (file & line number) for logs.
+function patchConsole() {
+  const customConsole = new Console({
+    stdout: process.stdout,
+    stderr: process.stderr,
+    colorMode: false,
+  });
+
+  const {error, info, warn} = customConsole;
+
+  const colorStrings = (method, color) => (...args) => {
+    let stringFound = false;
+    for (let i = 0; i < args.length; i++) {
+      const arg = args[i];
+      if (typeof arg === 'string') {
+        stringFound = true;
+        args[i] = color + arg;
+        break;
+      }
+    }
+
+    if (stringFound) {
+      args.push('\x1b[0m');
+    }
+
+    method(...args);
+  };
+
+  customConsole.error = colorStrings(error, '\x1b[31m');
+  customConsole.info = colorStrings(info, '\x1b[34m');
+  customConsole.warn = colorStrings(warn, '\x1b[33m');
+
+  //global.console = customConsole;
+}
+
 const env = jasmine.getEnv();
 env.beforeEach(() => {
+  patchConsole();
+
   global.mockClipboardCopy = jest.fn();
 
   // Test environment doesn't support document methods like execCommand()
diff --git a/packages/react-devtools-shared/src/backend/legacy/renderer.js b/packages/react-devtools-shared/src/backend/legacy/renderer.js
index f4d3def1766b66..091d755009b423 100644
--- a/packages/react-devtools-shared/src/backend/legacy/renderer.js
+++ b/packages/react-devtools-shared/src/backend/legacy/renderer.js
@@ -1007,11 +1007,6 @@ export function attach(
   const getProfilingData = () => {
     throw new Error('getProfilingData not supported by this renderer');
   };
-  const handleClonedForForceRemount = () => {
-    throw new Error(
-      'handleClonedForForceRemount not supported by this renderer',
-    );
-  };
   const handleCommitFiberRoot = () => {
     throw new Error('handleCommitFiberRoot not supported by this renderer');
   };
@@ -1089,7 +1084,6 @@ export function attach(
     getOwnersList,
     getPathForElement,
     getProfilingData,
-    handleClonedForForceRemount,
     handleCommitFiberRoot,
     handleCommitFiberUnmount,
     handlePostCommitFiberRoot,
diff --git a/packages/react-devtools-shared/src/backend/renderer.js b/packages/react-devtools-shared/src/backend/renderer.js
index 476a1781e0791e..13a8e1b34a8eca 100644
--- a/packages/react-devtools-shared/src/backend/renderer.js
+++ b/packages/react-devtools-shared/src/backend/renderer.js
@@ -636,7 +636,7 @@ export function attach(
     // Fortunately we would only leak Fibers that have errors/warnings associated with them,
     // which is hopefully only a small set and only in DEV mode– but this is still not great.
     // We should clean up Fibers like this when flushing; see recordPendingErrorsAndWarnings().
-    const fiberID = getFiberID(getPrimaryFiber(fiber));
+    const fiberID = getOrGenerateFiberID(fiber);
 
     if (__DEBUG__) {
       debug('onErrorOrWarning', fiber, null, `${type}: "${message}"`);
@@ -707,17 +707,19 @@ export function attach(
       const displayName =
         fiber.tag + ':' + (getDisplayNameForFiber(fiber) || 'null');
 
-      const id = getFiberIDSafe(fiber) || '-';
+      const maybeID = getFiberIDUnsafe(fiber) || '<no id>';
       const parentDisplayName = parentFiber
         ? parentFiber.tag +
           ':' +
           (getDisplayNameForFiber(parentFiber) || 'null')
         : '';
-      const parentID = parentFiber ? getFiberIDSafe(parentFiber) || '-' : '';
+      const maybeParentID = parentFiber
+        ? getFiberIDUnsafe(parentFiber) || '<no-id>'
+        : '';
 
       console.log(
-        `[renderer] %c${name} %c${displayName} (${id}) %c${
-          parentFiber ? `${parentDisplayName} (${parentID})` : ''
+        `[renderer] %c${name} %c${displayName} (${maybeID}) %c${
+          parentFiber ? `${parentDisplayName} (${maybeParentID})` : ''
         } %c${extraString}`,
         'color: red; font-weight: bold;',
         'color: blue;',
@@ -802,7 +804,7 @@ export function attach(
 
     // Recursively unmount all roots.
     hook.getFiberRoots(rendererID).forEach(root => {
-      currentRootID = getFiberID(getPrimaryFiber(root.current));
+      currentRootID = getOrGenerateFiberID(root.current);
       // The TREE_OPERATION_REMOVE_ROOT operation serves two purposes:
       // 1. It avoids sending unnecessary bridge traffic to clear a root.
       // 2. It preserves Fiber IDs when remounting (below) which in turn ID to error/warning mapping.
@@ -818,7 +820,7 @@ export function attach(
 
     // Recursively re-mount all roots with new filter criteria applied.
     hook.getFiberRoots(rendererID).forEach(root => {
-      currentRootID = getFiberID(getPrimaryFiber(root.current));
+      currentRootID = getOrGenerateFiberID(root.current);
       setRootPseudoKey(currentRootID, root.current);
       mountFiberRecursively(root.current, null, false, false);
       flushPendingEvents(root);
@@ -949,25 +951,16 @@ export function attach(
     }
   }
 
-  // This is a slightly annoying indirection.
-  // It is currently necessary because DevTools wants to use unique objects as keys for instances.
-  // However fibers have two versions.
-  // We use this set to remember first encountered fiber for each conceptual instance.
-  function getPrimaryFiber(fiber: Fiber): Fiber {
-    if (primaryFibers.has(fiber)) {
-      return fiber;
-    }
-    const {alternate} = fiber;
-    if (alternate != null && primaryFibers.has(alternate)) {
-      return alternate;
-    }
-    primaryFibers.add(fiber);
-    return fiber;
-  }
-
+  // Map of one or more Fibers in a pair to their unique id number.
+  // We track both Fibers to support Fast Refresh,
+  // which may forcefully replace one of the pair as part of hot reloading.
+  // In that case it's still important to be able to locate the previous ID during subsequent renders.
   const fiberToIDMap: Map<Fiber, number> = new Map();
-  const idToFiberMap: Map<number, Fiber> = new Map();
-  const primaryFibers: Set<Fiber> = new Set();
+
+  // Map of id to one (arbitrary) Fiber in a pair.
+  // This Map is used to e.g. get the display name for a Fiber or schedule an update,
+  // operations that should be the same whether the current and work-in-progress Fiber is used.
+  const idToArbitraryFiberMap: Map<number, Fiber> = new Map();
 
   // When profiling is supported, we store the latest tree base durations for each Fiber.
   // This is so that we can quickly capture a snapshot of those values if profiling starts.
@@ -982,30 +975,77 @@ export function attach(
   // When a mount or update is in progress, this value tracks the root that is being operated on.
   let currentRootID: number = -1;
 
-  function getFiberIDSafe(fiber: Fiber): number | null {
-    let primaryFiber = null;
-    if (primaryFibers.has(fiber)) {
-      primaryFiber = fiber;
+  function getOrGenerateFiberID(fiber: Fiber): number {
+    let id = null;
+    if (fiberToIDMap.has(fiber)) {
+      id = fiberToIDMap.get(fiber);
+    } else {
+      const {alternate} = fiber;
+      if (alternate !== null && fiberToIDMap.has(alternate)) {
+        id = fiberToIDMap.get(alternate);
+      }
+    }
+
+    if (id === null) {
+      id = getUID();
+    }
+
+    // This refinement is for Flow purposes only.
+    const refinedID = ((id: any): number);
+
+    // Make sure we're tracking this Fiber
+    // e.g. if it just mounted or an error was logged during initial render.
+    if (!fiberToIDMap.has(fiber)) {
+      fiberToIDMap.set(fiber, refinedID);
+      idToArbitraryFiberMap.set(refinedID, fiber);
     }
+
+    // Also make sure we're tracking its alternate,
+    // e.g. in case this is the first update after mount.
     const {alternate} = fiber;
-    if (alternate != null && primaryFibers.has(alternate)) {
-      primaryFiber = alternate;
+    if (alternate !== null) {
+      if (!fiberToIDMap.has(alternate)) {
+        fiberToIDMap.set(alternate, refinedID);
+      }
     }
 
-    if (primaryFiber && fiberToIDMap.has(primaryFiber)) {
-      return ((fiberToIDMap.get(primaryFiber): any): number);
+    return refinedID;
+  }
+
+  function getFiberIDThrows(fiber: Fiber): number {
+    const maybeID = getFiberIDUnsafe(fiber);
+    if (maybeID !== null) {
+      return maybeID;
     }
+    throw Error(
+      `Could not find ID for Fiber "${getDisplayNameForFiber(fiber) || ''}"`,
+    );
+  }
 
+  function getFiberIDUnsafe(fiber: Fiber): number | null {
+    if (fiberToIDMap.has(fiber)) {
+      return ((fiberToIDMap.get(fiber): any): number);
+    } else {
+      const {alternate} = fiber;
+      if (alternate !== null && fiberToIDMap.has(alternate)) {
+        return ((fiberToIDMap.get(alternate): any): number);
+      }
+    }
     return null;
   }
 
-  function getFiberID(primaryFiber: Fiber): number {
-    if (!fiberToIDMap.has(primaryFiber)) {
-      const id = getUID();
-      fiberToIDMap.set(primaryFiber, id);
-      idToFiberMap.set(id, primaryFiber);
+  function untrackFiberID(fiber: Fiber) {
+    const fiberID = getFiberIDUnsafe(fiber);
+    if (fiberID !== null) {
+      idToArbitraryFiberMap.delete(fiberID);
+    }
+
+    fiberToIDMap.delete(fiber);
+
+    const {alternate} = fiber;
+    if (alternate !== null) {
+      fiberToIDMap.delete(alternate);
     }
-    return ((fiberToIDMap.get(primaryFiber): any): number);
   }
 
   function getChangeDescription(
@@ -1066,7 +1106,7 @@ export function attach(
     switch (getElementTypeForFiber(fiber)) {
       case ElementTypeClass:
         if (idToContextsMap !== null) {
-          const id = getFiberID(getPrimaryFiber(fiber));
+          const id = getFiberIDThrows(fiber);
           const contexts = getContextsForFiber(fiber);
           if (contexts !== null) {
             idToContextsMap.set(id, contexts);
@@ -1122,7 +1162,7 @@ export function attach(
     switch (getElementTypeForFiber(fiber)) {
       case ElementTypeClass:
         if (idToContextsMap !== null) {
-          const id = getFiberID(getPrimaryFiber(fiber));
+          const id = getFiberIDThrows(fiber);
           const prevContexts = idToContextsMap.has(id)
             ? idToContextsMap.get(id)
             : null;
@@ -1390,15 +1430,13 @@ export function attach(
     clearPendingErrorsAndWarningsAfterDelay();
 
     fibersWithChangedErrorOrWarningCounts.forEach(fiberID => {
-      const fiber = idToFiberMap.get(fiberID);
+      const fiber = idToArbitraryFiberMap.get(fiberID);
       if (fiber != null) {
         // Don't send updates for Fibers that didn't mount due to e.g. Suspense or an error boundary.
         // We may also need to clean up after ourselves to avoid leaks.
         // See inline comments in onErrorOrWarning() for more info.
         if (isFiberMountedImpl(fiber) !== MOUNTED) {
-          fiberToIDMap.delete(fiber);
-          idToFiberMap.delete(fiberID);
-          primaryFibers.delete(fiber);
+          untrackFiberID(fiber);
           return;
         }
 
@@ -1559,7 +1597,7 @@ export function attach(
     }
 
     const isRoot = fiber.tag === HostRoot;
-    const id = getFiberID(getPrimaryFiber(fiber));
+    const id = getOrGenerateFiberID(fiber);
 
     const hasOwnerMetadata = fiber.hasOwnProperty('_debugOwner');
     const isProfilingSupported = fiber.hasOwnProperty('treeBaseDuration');
@@ -1582,11 +1620,8 @@ export function attach(
       const elementType = getElementTypeForFiber(fiber);
       const {_debugOwner} = fiber;
 
-      const ownerID =
-        _debugOwner != null ? getFiberID(getPrimaryFiber(_debugOwner)) : 0;
-      const parentID = parentFiber
-        ? getFiberID(getPrimaryFiber(parentFiber))
-        : 0;
+      const ownerID = _debugOwner != null ? getFiberIDThrows(_debugOwner) : 0;
+      const parentID = parentFiber ? getFiberIDThrows(parentFiber) : 0;
 
       const displayNameStringID = getStringID(displayName);
 
@@ -1621,6 +1656,18 @@ export function attach(
       );
     }
 
+    const unsafeID = getFiberIDUnsafe(fiber);
+    if (fiber._debugNeedsRemount) {
+      if (unsafeID === null) {
+        // This is a case we can't recover from.
+        setTimeout(() => {
+          // TODO (bvaughn) Document this
+          updateComponentFilters([]);
+        }, 0);
+        return;
+      }
+    }
+
     if (trackedPathMatchFiber !== null) {
       // We're in the process of trying to restore previous selection.
       // If this fiber matched but is being unmounted, there's no use trying.
@@ -1633,9 +1680,7 @@ export function attach(
       }
     }
 
-    const isRoot = fiber.tag === HostRoot;
-    const primaryFiber = getPrimaryFiber(fiber);
-    if (!fiberToIDMap.has(primaryFiber)) {
+    if (unsafeID === null) {
       // If we've never seen this Fiber, it might be inside of a legacy render Suspense fragment (so the store is not even aware of it).
       // In that case we can just ignore it or it will cause errors later on.
       // One example of this is a Lazy component that never resolves before being unmounted.
@@ -1643,10 +1688,12 @@ export function attach(
       // TODO: This is fragile and can obscure actual bugs.
       //
       // Calling getPrimaryFiber() lazily adds fibers to the Map, so clean up after ourselves before returning.
-      primaryFibers.delete(primaryFiber);
       return;
     }
-    const id = getFiberID(primaryFiber);
+
+    // Flow refinement.
+    const id = ((unsafeID: any): number);
+    const isRoot = fiber.tag === HostRoot;
     if (isRoot) {
       // Roots must be removed only after all children (pending and simulated) have been removed.
       // So we track it separately.
@@ -1662,14 +1709,14 @@ export function attach(
       }
     }
 
-    fiberToIDMap.delete(primaryFiber);
-    idToFiberMap.delete(id);
-    primaryFibers.delete(primaryFiber);
+    if (!fiber._debugNeedsRemount) {
+      untrackFiberID(fiber);
 
-    const isProfilingSupported = fiber.hasOwnProperty('treeBaseDuration');
-    if (isProfilingSupported) {
-      idToRootMap.delete(id);
-      idToTreeBaseDurationMap.delete(id);
+      const isProfilingSupported = fiber.hasOwnProperty('treeBaseDuration');
+      if (isProfilingSupported) {
+        idToRootMap.delete(id);
+        idToTreeBaseDurationMap.delete(id);
+      }
     }
   }
 
@@ -1696,6 +1743,9 @@ export function attach(
       const shouldIncludeInTree = !shouldFilterFiber(fiber);
       if (shouldIncludeInTree) {
         recordMount(fiber, parentFiber);
+      } else {
+        // Generate an ID even for filtered Fibers, in case it's needed later (e.g. for Profiling).
+        getOrGenerateFiberID(fiber);
       }
 
       if (traceUpdatesEnabled) {
@@ -1806,7 +1856,7 @@ export function attach(
   }
 
   function recordProfilingDurations(fiber: Fiber) {
-    const id = getFiberID(getPrimaryFiber(fiber));
+    const id = getFiberIDThrows(fiber);
     const {actualDuration, treeBaseDuration} = fiber;
 
     idToTreeBaseDurationMap.set(id, treeBaseDuration || 0);
@@ -1894,7 +1944,7 @@ export function attach(
       return;
     }
     pushOperation(TREE_OPERATION_REORDER_CHILDREN);
-    pushOperation(getFiberID(getPrimaryFiber(fiber)));
+    pushOperation(getFiberIDThrows(fiber));
     pushOperation(numChildren);
     for (let i = 0; i < nextChildren.length; i++) {
       pushOperation(nextChildren[i]);
@@ -1906,7 +1956,7 @@ export function attach(
     nextChildren: Array<number>,
   ) {
     if (!shouldFilterFiber(fiber)) {
-      nextChildren.push(getFiberID(getPrimaryFiber(fiber)));
+      nextChildren.push(getFiberIDThrows(fiber));
     } else {
       let child = fiber.child;
       const isTimedOutSuspense =
@@ -1944,6 +1994,8 @@ export function attach(
       debug('updateFiberRecursively()', nextFiber, parentFiber);
     }
 
+    const id = getOrGenerateFiberID(nextFiber);
+
     if (traceUpdatesEnabled) {
       const elementType = getElementTypeForFiber(nextFiber);
       if (traceNearestHostComponentUpdate) {
@@ -1969,8 +2021,7 @@ export function attach(
 
     if (
       mostRecentlyInspectedElement !== null &&
-      mostRecentlyInspectedElement.id ===
-        getFiberID(getPrimaryFiber(nextFiber)) &&
+      mostRecentlyInspectedElement.id === id &&
       didFiberRender(prevFiber, nextFiber)
     ) {
       // If this Fiber has updated, clear cached inspected data.
@@ -2114,7 +2165,7 @@ export function attach(
           // we should fall back to recursively marking the nearest host descendants for highlight.
           if (traceNearestHostComponentUpdate) {
             const hostFibers = findAllCurrentHostFibers(
-              getFiberID(getPrimaryFiber(nextFiber)),
+              getFiberIDThrows(nextFiber),
             );
             hostFibers.forEach(hostFiber => {
               traceUpdatesForNodes.add(hostFiber.stateNode);
@@ -2198,7 +2249,7 @@ export function attach(
       }
       // If we have not been profiling, then we can just walk the tree and build up its current state as-is.
       hook.getFiberRoots(rendererID).forEach(root => {
-        currentRootID = getFiberID(getPrimaryFiber(root.current));
+        currentRootID = getOrGenerateFiberID(root.current);
         setRootPseudoKey(currentRootID, root.current);
 
         // Handle multi-renderer edge-case where only some v16 renderers support profiling.
@@ -2253,7 +2304,7 @@ export function attach(
     const current = root.current;
     const alternate = current.alternate;
 
-    currentRootID = getFiberID(getPrimaryFiber(current));
+    currentRootID = getOrGenerateFiberID(current);
 
     // Before the traversals, remember to start tracking
     // our path in case we have selection to restore.
@@ -2399,7 +2450,7 @@ export function attach(
   }
 
   function getDisplayNameForFiberID(id) {
-    const fiber = idToFiberMap.get(id);
+    const fiber = idToArbitraryFiberMap.get(id);
     return fiber != null ? getDisplayNameForFiber(((fiber: any): Fiber)) : null;
   }
 
@@ -2414,7 +2465,7 @@ export function attach(
           fiber = fiber.return;
         }
       }
-      return getFiberID(getPrimaryFiber(((fiber: any): Fiber)));
+      return getFiberIDThrows(((fiber: any): Fiber));
     }
     return null;
   }
@@ -2484,7 +2535,7 @@ export function attach(
   // It would be nice if we updated React to inject this function directly (vs just indirectly via findDOMNode).
   // BEGIN copied code
   function findCurrentFiberUsingSlowPathById(id: number): Fiber | null {
-    const fiber = idToFiberMap.get(id);
+    const fiber = idToArbitraryFiberMap.get(id);
     if (fiber == null) {
       console.warn(`Could not find Fiber with id "${id}"`);
       return null;
@@ -2646,7 +2697,7 @@ export function attach(
   }
 
   function prepareViewElementSource(id: number): void {
-    const fiber = idToFiberMap.get(id);
+    const fiber = idToArbitraryFiberMap.get(id);
     if (fiber == null) {
       console.warn(`Could not find Fiber with id "${id}"`);
       return;
@@ -2680,7 +2731,7 @@ export function attach(
   function fiberToSerializedElement(fiber: Fiber): SerializedElement {
     return {
       displayName: getDisplayNameForFiber(fiber) || 'Anonymous',
-      id: getFiberID(getPrimaryFiber(fiber)),
+      id: getFiberIDThrows(fiber),
       key: fiber.key,
       type: getElementTypeForFiber(fiber),
     };
@@ -3011,7 +3062,7 @@ export function attach(
   function updateSelectedElement(inspectedElement: InspectedElement): void {
     const {hooks, id, props} = inspectedElement;
 
-    const fiber = idToFiberMap.get(id);
+    const fiber = idToArbitraryFiberMap.get(id);
     if (fiber == null) {
       console.warn(`Could not find Fiber with id "${id}"`);
       return;
@@ -3529,7 +3580,7 @@ export function attach(
     idToContextsMap = new Map();
 
     hook.getFiberRoots(rendererID).forEach(root => {
-      const rootID = getFiberID(getPrimaryFiber(root.current));
+      const rootID = getFiberIDThrows(root.current);
       ((displayNamesByRootID: any): DisplayNamesByRootID).set(
         rootID,
         getDisplayNameForRoot(root.current),
@@ -3572,8 +3623,8 @@ export function attach(
 
   const forceFallbackForSuspenseIDs = new Set();
   function shouldSuspendFiberAccordingToSet(fiber) {
-    const id = getFiberID(getPrimaryFiber(((fiber: any): Fiber)));
-    return forceFallbackForSuspenseIDs.has(id);
+    const maybeID = getFiberIDUnsafe(((fiber: any): Fiber));
+    return maybeID !== null && forceFallbackForSuspenseIDs.has(maybeID);
   }
 
   function overrideSuspense(id, forceFallback) {
@@ -3598,7 +3649,7 @@ export function attach(
         setSuspenseHandler(shouldSuspendFiberAlwaysFalse);
       }
     }
-    const fiber = idToFiberMap.get(id);
+    const fiber = idToArbitraryFiberMap.get(id);
     if (fiber != null) {
       scheduleUpdate(fiber);
     }
@@ -3749,7 +3800,7 @@ export function attach(
       case HostRoot:
         // Roots don't have a real displayName, index, or key.
         // Instead, we'll use the pseudo key (childDisplayName:indexWithThatName).
-        const id = getFiberID(getPrimaryFiber(fiber));
+        const id = getFiberIDThrows(fiber);
         const pseudoKey = rootPseudoKeys.get(id);
         if (pseudoKey === undefined) {
           throw new Error('Expected mounted root to have known pseudo key.');
@@ -3774,7 +3825,7 @@ export function attach(
   // The return path will contain Fibers that are "invisible" to the store
   // because their keys and indexes are important to restoring the selection.
   function getPathForElement(id: number): Array<PathFrame> | null {
-    let fiber = idToFiberMap.get(id);
+    let fiber = idToArbitraryFiberMap.get(id);
     if (fiber == null) {
       return null;
     }
@@ -3805,7 +3856,7 @@ export function attach(
       return null;
     }
     return {
-      id: getFiberID(getPrimaryFiber(fiber)),
+      id: getFiberIDThrows(fiber),
       isFullMatch: trackedPathMatchDepth === trackedPath.length - 1,
     };
   }
@@ -3836,41 +3887,6 @@ export function attach(
     traceUpdatesEnabled = isEnabled;
   }
 
-  function handleClonedForForceRemount(oldFiber: Fiber, newFiber: Fiber): void {
-    if (__DEBUG__) {
-      console.log(
-        '[renderer] handleClonedForForceRemount',
-        getDisplayNameForFiber(oldFiber),
-        '(' + getFiberID(getPrimaryFiber(oldFiber)),
-        '->',
-        getFiberID(getPrimaryFiber(newFiber)) + ')',
-      );
-    }
-
-    let primaryFiber = null;
-    if (primaryFibers.has(oldFiber)) {
-      primaryFiber = oldFiber;
-    }
-    const {alternate} = oldFiber;
-    if (alternate != null && primaryFibers.has(alternate)) {
-      primaryFiber = alternate;
-    }
-
-    // Fast Refresh is about to (synchronously) clone and replace this part of the tree.
-    // In order to avoid these Fibers from leaking on the DevTools side,
-    // and possibly remaining visible in the Components tab as well,
-    // queue up unmount operations to send on the next commit.
-    if (primaryFiber) {
-      recordUnmount(primaryFiber, false);
-      unmountFiberChildrenRecursively(primaryFiber);
-
-      const fiberID = ((fiberToIDMap.get(primaryFiber): any): number);
-      fiberToIDMap.delete(primaryFiber);
-      idToFiberMap.delete(fiberID);
-      primaryFibers.delete(primaryFiber);
-    }
-  }
-
   return {
     cleanup,
     clearErrorsAndWarnings,
@@ -3887,7 +3903,6 @@ export function attach(
     getOwnersList,
     getPathForElement,
     getProfilingData,
-    handleClonedForForceRemount,
     handleCommitFiberRoot,
     handleCommitFiberUnmount,
     handlePostCommitFiberRoot,
diff --git a/packages/react-devtools-shared/src/backend/types.js b/packages/react-devtools-shared/src/backend/types.js
index 5fc0950791e465..342931c250eab5 100644
--- a/packages/react-devtools-shared/src/backend/types.js
+++ b/packages/react-devtools-shared/src/backend/types.js
@@ -323,7 +323,6 @@ export type RendererInterface = {
   getProfilingData(): ProfilingDataBackend,
   getOwnersList: (id: number) => Array<SerializedElement> | null,
   getPathForElement: (id: number) => Array<PathFrame> | null,
-  handleClonedForForceRemount: (oldFiber: Fiber, newFiber: Fiber) => void,
   handleCommitFiberRoot: (fiber: Object, commitPriority?: number) => void,
   handleCommitFiberUnmount: (fiber: Object) => void,
   handlePostCommitFiberRoot: (fiber: Object) => void,
@@ -397,12 +396,5 @@ export type DevToolsHook = {
     // Added in v16.9 to support Fast Refresh
     didError?: boolean,
   ) => void,
-
-  // Added in v17.x to improve Fast Refresh + DevTools integration
-  onClonedForForceRemount: (
-    rendererID: RendererID,
-    oldFiber: Fiber,
-    newFiber: Fiber,
-  ) => void,
   ...
 };
diff --git a/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/ErrorBoundary.js b/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/ErrorBoundary.js
index 45441a925df655..63c67afdd9bc25 100644
--- a/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/ErrorBoundary.js
+++ b/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/ErrorBoundary.js
@@ -21,6 +21,7 @@ type Props = {|
 
 type State = {|
   callStack: string | null,
+  canDismiss: boolean,
   componentStack: string | null,
   errorMessage: string | null,
   hasError: boolean,
@@ -28,6 +29,7 @@ type State = {|
 
 const InitialState: State = {
   callStack: null,
+  canDismiss: false,
   componentStack: null,
   errorMessage: null,
   hasError: false,
@@ -77,13 +79,20 @@ export default class ErrorBoundary extends Component<Props, State> {
 
   render() {
     const {children} = this.props;
-    const {callStack, componentStack, errorMessage, hasError} = this.state;
+    const {
+      callStack,
+      canDismiss,
+      componentStack,
+      errorMessage,
+      hasError,
+    } = this.state;
 
     if (hasError) {
       return (
         <ErrorView
           callStack={callStack}
           componentStack={componentStack}
+          dismissError={canDismiss ? this._dismissError : null}
           errorMessage={errorMessage}>
           <Suspense fallback={<SearchingGitHubIssues />}>
             <SuspendingErrorView
@@ -99,9 +108,16 @@ export default class ErrorBoundary extends Component<Props, State> {
     return children;
   }
 
+  _dismissError = () => {
+    this.setState(InitialState);
+  };
+
   _onStoreError = (error: Error) => {
     if (!this.state.hasError) {
-      this.setState(ErrorBoundary.getDerivedStateFromError(error));
+      this.setState({
+        ...ErrorBoundary.getDerivedStateFromError(error),
+        canDismiss: true,
+      });
     }
   };
 }
diff --git a/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/ErrorView.js b/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/ErrorView.js
index 6ec792408fe9c8..65898c5e553d7b 100644
--- a/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/ErrorView.js
+++ b/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/ErrorView.js
@@ -8,12 +8,14 @@
  */
 
 import * as React from 'react';
+import Button from 'react-devtools-shared/src/devtools/views/Button';
 import styles from './shared.css';
 
 type Props = {|
   callStack: string | null,
   children: React$Node,
   componentStack: string | null,
+  dismissError: Function | null,
   errorMessage: string | null,
 |};
 
@@ -21,14 +23,20 @@ export default function ErrorView({
   callStack,
   children,
   componentStack,
+  dismissError = null,
   errorMessage,
 }: Props) {
   return (
     <div className={styles.ErrorBoundary}>
       {children}
       <div className={styles.ErrorInfo}>
-        <div className={styles.Header}>
-          Uncaught Error: {errorMessage || ''}
+        <div className={styles.HeaderRow}>
+          <div className={styles.Header}>
+            Uncaught Error: {errorMessage || ''}
+          </div>
+          {dismissError !== null && (
+            <Button onClick={dismissError}>Dismiss</Button>
+          )}
         </div>
         {!!callStack && (
           <div className={styles.Stack}>
diff --git a/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/shared.css b/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/shared.css
index 267cfad7b7e886..05988649e01cfe 100644
--- a/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/shared.css
+++ b/packages/react-devtools-shared/src/devtools/views/ErrorBoundary/shared.css
@@ -37,12 +37,22 @@
   overflow: auto;
 }
 
-.Header {
+.HeaderRow {
+  display: flex;
+  flex-direction: row;
   font-size: var(--font-size-sans-large);
   font-weight: bold;
   color: var(--color-error-text);
 }
 
+.Header {
+  flex: 1 1 auto;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  min-width: 0;
+}
+
 .Stack {
   margin-top: 0.5rem;
   white-space: pre-wrap;
@@ -75,9 +85,13 @@
 .ReproSteps {
   margin-left: 0.25rem;
   color: var(--color-console-warning-text);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  min-width: 0;
 }
 
 .UpdateExistingIssuePrompt {
   margin-right: 0.25rem;
   color: var(--color-console-warning-text);
-}
\ No newline at end of file
+}
diff --git a/packages/react-devtools-shared/src/hook.js b/packages/react-devtools-shared/src/hook.js
index d636a683d526b3..a4724f6f6b92b0 100644
--- a/packages/react-devtools-shared/src/hook.js
+++ b/packages/react-devtools-shared/src/hook.js
@@ -261,13 +261,6 @@ export function installHook(target: any): DevToolsHook | null {
     return roots[rendererID];
   }
 
-  function onClonedForForceRemount(rendererID, oldFiber, newFiber) {
-    const rendererInterface = rendererInterfaces.get(rendererID);
-    if (rendererInterface != null) {
-      rendererInterface.handleClonedForForceRemount(oldFiber, newFiber);
-    }
-  }
-
   function onCommitFiberUnmount(rendererID, fiber) {
     const rendererInterface = rendererInterfaces.get(rendererID);
     if (rendererInterface != null) {
@@ -313,7 +306,6 @@ export function installHook(target: any): DevToolsHook | null {
 
     // Fast Refresh for web relies on this.
     renderers,
-    onClonedForForceRemount,
 
     emit,
     getFiberRoots,
diff --git a/packages/react-reconciler/src/ReactFiberBeginWork.new.js b/packages/react-reconciler/src/ReactFiberBeginWork.new.js
index 44dc1caefeeb60..2dfc6766577f95 100644
--- a/packages/react-reconciler/src/ReactFiberBeginWork.new.js
+++ b/packages/react-reconciler/src/ReactFiberBeginWork.new.js
@@ -32,10 +32,6 @@ import type {UpdateQueue} from './ReactUpdateQueue.new';
 
 import checkPropTypes from 'shared/checkPropTypes';
 
-import {
-  isDevToolsPresent,
-  onClonedForForceRemount,
-} from './ReactFiberDevToolsHook.new';
 import {
   IndeterminateComponent,
   FunctionComponent,
@@ -3198,21 +3194,19 @@ function beginWork(
 
   if (__DEV__) {
     if (workInProgress._debugNeedsRemount && current !== null) {
-      const clonedWorkInProgress = createFiberFromTypeAndProps(
-        workInProgress.type,
-        workInProgress.key,
-        workInProgress.pendingProps,
-        workInProgress._debugOwner || null,
-        workInProgress.mode,
-        workInProgress.lanes,
-      );
-
-      if (isDevToolsPresent) {
-        onClonedForForceRemount(workInProgress, clonedWorkInProgress);
-      }
-
       // This will restart the begin phase with a new fiber.
-      return remountFiber(current, workInProgress, clonedWorkInProgress);
+      return remountFiber(
+        current,
+        workInProgress,
+        createFiberFromTypeAndProps(
+          workInProgress.type,
+          workInProgress.key,
+          workInProgress.pendingProps,
+          workInProgress._debugOwner || null,
+          workInProgress.mode,
+          workInProgress.lanes,
+        ),
+      );
     }
   }
 
diff --git a/packages/react-reconciler/src/ReactFiberBeginWork.old.js b/packages/react-reconciler/src/ReactFiberBeginWork.old.js
index a3293218e9ea51..7c9df820b98c53 100644
--- a/packages/react-reconciler/src/ReactFiberBeginWork.old.js
+++ b/packages/react-reconciler/src/ReactFiberBeginWork.old.js
@@ -32,10 +32,6 @@ import type {UpdateQueue} from './ReactUpdateQueue.old';
 
 import checkPropTypes from 'shared/checkPropTypes';
 
-import {
-  isDevToolsPresent,
-  onClonedForForceRemount,
-} from './ReactFiberDevToolsHook.old';
 import {
   IndeterminateComponent,
   FunctionComponent,
@@ -3198,21 +3194,19 @@ function beginWork(
 
   if (__DEV__) {
     if (workInProgress._debugNeedsRemount && current !== null) {
-      const clonedWorkInProgress = createFiberFromTypeAndProps(
-        workInProgress.type,
-        workInProgress.key,
-        workInProgress.pendingProps,
-        workInProgress._debugOwner || null,
-        workInProgress.mode,
-        workInProgress.lanes,
-      );
-
-      if (isDevToolsPresent) {
-        onClonedForForceRemount(workInProgress, clonedWorkInProgress);
-      }
-
       // This will restart the begin phase with a new fiber.
-      return remountFiber(current, workInProgress, clonedWorkInProgress);
+      return remountFiber(
+        current,
+        workInProgress,
+        createFiberFromTypeAndProps(
+          workInProgress.type,
+          workInProgress.key,
+          workInProgress.pendingProps,
+          workInProgress._debugOwner || null,
+          workInProgress.mode,
+          workInProgress.lanes,
+        ),
+      );
     }
   }
 
diff --git a/packages/react-reconciler/src/ReactFiberDevToolsHook.new.js b/packages/react-reconciler/src/ReactFiberDevToolsHook.new.js
index 9d2f9243a2752a..e7bde59e20cbaf 100644
--- a/packages/react-reconciler/src/ReactFiberDevToolsHook.new.js
+++ b/packages/react-reconciler/src/ReactFiberDevToolsHook.new.js
@@ -166,28 +166,3 @@ export function onCommitUnmount(fiber: Fiber) {
     }
   }
 }
-
-export function onClonedForForceRemount(
-  oldWorkInProgress: Fiber,
-  newWorkInProgress: Fiber,
-) {
-  if (
-    injectedHook &&
-    typeof injectedHook.onClonedForForceRemount === 'function'
-  ) {
-    try {
-      injectedHook.onClonedForForceRemount(
-        rendererID,
-        oldWorkInProgress,
-        newWorkInProgress,
-      );
-    } catch (err) {
-      if (__DEV__) {
-        if (!hasLoggedError) {
-          hasLoggedError = true;
-          console.error('React instrumentation encountered an error: %s', err);
-        }
-      }
-    }
-  }
-}
diff --git a/packages/react-reconciler/src/ReactFiberDevToolsHook.old.js b/packages/react-reconciler/src/ReactFiberDevToolsHook.old.js
index 198e6233c0b9d4..494138685e1045 100644
--- a/packages/react-reconciler/src/ReactFiberDevToolsHook.old.js
+++ b/packages/react-reconciler/src/ReactFiberDevToolsHook.old.js
@@ -166,28 +166,3 @@ export function onCommitUnmount(fiber: Fiber) {
     }
   }
 }
-
-export function onClonedForForceRemount(
-  oldWorkInProgress: Fiber,
-  newWorkInProgress: Fiber,
-) {
-  if (
-    injectedHook &&
-    typeof injectedHook.onClonedForForceRemount === 'function'
-  ) {
-    try {
-      injectedHook.onClonedForForceRemount(
-        rendererID,
-        oldWorkInProgress,
-        newWorkInProgress,
-      );
-    } catch (err) {
-      if (__DEV__) {
-        if (!hasLoggedError) {
-          hasLoggedError = true;
-          console.error('React instrumentation encountered an error: %s', err);
-        }
-      }
-    }
-  }
-}
diff --git a/packages/react-reconciler/src/ReactFiberHotReloading.new.js b/packages/react-reconciler/src/ReactFiberHotReloading.new.js
index 61ce24224c3e3b..4c9eaf010125c2 100644
--- a/packages/react-reconciler/src/ReactFiberHotReloading.new.js
+++ b/packages/react-reconciler/src/ReactFiberHotReloading.new.js
@@ -318,7 +318,6 @@ function scheduleFibersWithFamiliesRecursively(
     if (needsRemount) {
       fiber._debugNeedsRemount = true;
     }
-
     if (needsRemount || needsRender) {
       scheduleUpdateOnFiber(fiber, SyncLane, NoTimestamp);
     }
diff --git a/packages/react-reconciler/src/ReactFiberHotReloading.old.js b/packages/react-reconciler/src/ReactFiberHotReloading.old.js
index 475b449541d160..ee0616fae79c0b 100644
--- a/packages/react-reconciler/src/ReactFiberHotReloading.old.js
+++ b/packages/react-reconciler/src/ReactFiberHotReloading.old.js
@@ -318,7 +318,6 @@ function scheduleFibersWithFamiliesRecursively(
     if (needsRemount) {
       fiber._debugNeedsRemount = true;
     }
-
     if (needsRemount || needsRender) {
       scheduleUpdateOnFiber(fiber, SyncLane, NoTimestamp);
     }