Re left ctrl, btw, it’s possible now to map ctrl to esc. It’ll map both keys though—-the apple interface doesn’t do left/right.

It’s a “simple modification” (specific type) in Karabiner though, if you use that. I use PC mechanical keyboards so most of my typing devices a) have swapped around mod keys and b) map right ctrl to fn so I can do Mac device hotkeys from pc keyboard.