+1. The more lights you have controlled by home assistant, the more this feature is needed. I want to turn off all of my lights except for one in the kitchen, so I have to make a group of all of them except that one, and then when I add more lights, the scene breaks unless I remember to update that group. Then I want to turn off all of the lights except for one in the bedroom, so I have to make a group of all of them except that one, and when I add more lights I have to update both groups. Etc. You end up with a ton of huge groups and it’s not manageable.
I’ve been trying to work around this in scenes by turning off the group of all lights and then turning on the one light, but groups don’t seem to care about order and the behavior is unreliable. I’ve also tried using a script, but it waits for each light as it goes so it’s very slow.
As far as implementation goes, the most generally useful pattern I can think of would be something that allows both adding and subtracting entities to form a group as you go, like: