I only just started messing around with the button controller app this weekend and I wish I had used it sooner. I've already replaced several simple automation rules with a single button controller instance because you can define actions for multiple buttons for a device in one place.
I have a rule that turns the bathroom light on at 10pm at 6% and off at sunrise. So during the day I want button 2 to turn the light off, but from 10pm to sunrise, I want button 2 to return the dimmer level to 6%. There's not a way to test conditions in button manager that I could see, but I did manage to get around it by creating a "bathroom nightlight" scene and added a restriction that it can only be activated between 10pm and sunrise.
I have similar automations in other areas of the house and while there are workarounds, it would be nice if I could do it in one place. I know there is no performance downside to having multiple rules and multiple scenes, etc. but I'd rather have a single switch's behavior defined in one place. Mostly for ease of use so if I need to make changes or something isn't quite working right, I don't have to go check multi places.