@LRvdLinden just found your app while looking for an easy way to solve this. I was wondering if it might be possible to extend/duplicate some of the cards affecting multiple lights to read something like this:
Dim [[light_state]] lights for [[zone]] to [[%]]Set [[light_state]] lights to color [[color]] for [[zone]]- etc
With light state being either all (default), turned on or turned off.
Because I think only wanting to influence currently turned on lights in a room for example is a pretty common use case.