What I mean is, you manage the index with the same commands that you manage commits with. The emphasis is on "with separate tools" not "manage the index".

I am super curious as to what you mean specifically, but I also know that getting into details can be annoying, so if you have some specifics I'd love to hear more about them. I loved git's index so this isn't coming from a place of "the index sucks and you shouldn't care about it" it's "I think jj executes the index better than git does actually". But also if you don't, that's fine by me too, if you like a tool you should continue to use it.

(I never set autosquash either)