Thanks :)
Building the whole thing is certainly a fight with getting the physics engine to do the right thing. Certainly spend too much time getting the button collider to do proper weight calculation and in the end a trigger would probably be way more reliable. I guess most platformer mechanics would be a bit more reliable if it wasn't on top of the physics engine.
In the end a lot of the physics weirdness also made it fun to play (at least while debugging).