in the layers window it would be very nice to have the possibility to add a selection mask, instead of only a transparency mask. The difference is that I can put several selection masks in a paint layer group and turn them on and off. this does not work with transparency masks.

Hm? I can just make a selection, rightclick the layer and add a 'local selection'? Am I missing something here?

See https://docs.krita.org/en/reference_man ... masks.html

Ha, ok, my bad! I had not found that possibility yet. GREAT!