>That position for main modifier is so underrepresented and unknown

So True.

> Plus you don’t have to move your hand at all compared to bottom left main mod

I never use the bottom left mod. I'm on HHKB, so no caps lock, just ctrl. I agree that since switching to mac, I like using thumb for any mod key pressing. I think it's indeed superior: You just don't have to move you hand at all. E.g. for Ctrl-A,S for split pane in tmux, I sometimes get it wrong because my pinky is on Ctrl (caps lock position).

> If you don’t want the split you could build a Convolution that just released

Thanks for the suggestion! Looking into it...