Enacs shouldn't freeze like that tbh, I've been using Emacs + Magit for a while now and it doesn't freeze ever.

The exact described behavior has happened to me as well.

C-x 0 is the way out. That happens sometimes when focus shifts while the Transient hasn't properly exited.

ahhh that sounds like it would work, thanks

That's an issue with Transient, a dependency of Magit and also authored by me. It's complicated, but essentially the problem is that post-command-hook is not guaranteed to be run after the command. And the second problem is that I tried working around that for too long (and instead resorted to increasingly sophisticated and desperate heuristics), instead of getting it changed in Emacs. I've done that now, so maybe in Emacs 30.

But I have also switched to handling part of it using an around advice, which does work reliably. I've done that about two weeks ago, so changes are that if you update Transient now, you won't ever see that again.