I believe in sculp mode there ws a way for it, but I don’t remember which one was.
I was wondering if it was possible for edit mode as well.
I’m aditing object a, press a letter and you’re editing that other object, great when you’re moving from mesh to mesh a lot.
Thats transfer mode (Alt+Q) 
And yes it works in edit mode too.
object.transfer_mode
Damm! I had a pie menu there that I didn’t even use, just bc I messed up with some addon and that one was free to use!
I tried it on 3.4 after disabling that and it’s working! It even does a little flash animation. 