https://www.stavros.io/posts/switch-to-jujutsu-already-a-tut...
Also found https://github.com/gitbutlerapp/gitbutler
Does jj help with that at all?
I've experimented a bit with git-town.com (OSS) and now everyone at $DAYJOB uses graphite.com (SaaS) which does that part very well.
this is less of a problem if you're more into the 1 change == 1 commit workflow.