[Product page] Variant selection can lag on change

[kmeleta]

When a user selects a variant, the UI is not blocked to prevent rapid subsequent selections. This creates a weird visual lag that is made worse the more selections are made while new data is fetched. Slower connections will further exacerbate the effect.

Video and more details here #2025 (review)

We should look into either blocking the variant UI to prevent additional interactions or see if we can cancel/override the previous in-progress selections.

This behavior was introduced with the addition of the temporary sold out variant UI change #1407