That’s a problem created by GitHub or people unable to think outside of the GitHub model. It would make more sense to solve that problem through a review tool.
For what it’s worth from what I’ve read about JJ: it’s a better VCS frontend overall.
There are two distinct but related issues here: GitHub's terrible support for stacked PRs, and Git's `rebase -i` user interface to manage them which is quite bad. Jujutsu fixes the latter.
I maintain a fork of a tool called `spr` which comes as close to fixing the former as GH allows. It has a number of limitations, though. https://github.com/sunshowers/spr
