I have a similar scenario, just with two Buttons, on the dimmer switch. So i have no condition “if on” / “if off”. But i also can switch light on an increase brightness with one Button - i just say “on hold increase by xx %” and xx is < 100. So it every hold that gets recognized increase the Brightness by e.g. 10% and when i just Keep Holding the same Button the Event gets triggert multiple times and dimming works.
Edit:
Where did you find the “stop brightness change” Action?