The problem is that once you're airborne, you can't opt to transform or not. Since you need to hold C to be able to transform, you need to decide that you're going to do it in advance. Personally a lot of times I quickly transform when I realise I'm about to fall into a hazard; I can't do it with this system. Also, B+C? That's pretty cryptic. Personally I'd go for full-blown A+B+C, and be able to test it in midair. Can still be compatible with debug by making it check for C being pressed, then checking B (branching out of the edit mode toggle) and finally checking A.