I actually think I'll keep working on it too. I think it'd help with the back extension roll thing in gymnastics, which in turn would help me get chakrasana in yoga. Right now I just don't have the timing on any of those. On Monday I saw a guy doing back extension rolls and he was clearly on the edges of his hands as he pushed up, then flipped to his palms. Weird! I didn't ask him why he was doing that but maybe I will next week.

As for cartwheeling out, ok, assume there's no step taken with the hands, so you're just going over backwards. You twist 1/4 twist, now your body/foot are coming down sideways. But your hands are still pointing back in the direction that foot is coming down in.

That's not a position my forearms and wrists can get into if I just try to stand like that on the floor, and it's possible you never actually are in that position, if enough weight comes off the hands that they can twist/rotate somewhat on the floor as you're coming down. I mean, I can cartwheel, so if I did take a step with one hand, and used that step to turn the hand inward pointing at the other hand, then maybe I could come down okay.

Hope this concern is clear... I would like to be able to do this precisely so I can work on hard surfaces.