Last time I checked the underlying daemon, libratbag, didn't have support for the G502X wireless mouse and although there were Issues and Pull Requests open, no movement had been made towards getting those in.

I also use this, but Piper seems to barely work. Any time I try to rebind keys, it usually errors out with something incomprehensible. Their GitHub seems to talk in circles about it, either blaming you (not the correct response) or throwing up their hands.

Yeah, I've been using this for a long time, works fine.