Question: Run on one exact layer only / ignore layers

[majkaz]

Is there a way to get the plugin to run the tracing from one exact layer only? Or to ignore certain layers?

Reason:
I am using this plugin to select buildings exclusively from the Czech CUZK:KM, where the buildings are still missing from the preferred source (CUZK:RUIAN, with its own tracing plugin). Ideally, I have several layers switched on - at least both these and often several others (DigitalGlobe, for example). This is cumbersome - for the plugin to work as I would like it, I have to switch off all the "additional" layers before running the areaselector.

Thank you for the plugin, by the way. It works nicely.