There have been various proposals over the years for how to integrate issues and reviews in the distributed git tree itself (http://dist-bugs.branchable.com/software/), but I don't think any of them have really gone anywhere, certainly not in terms of support by the hosted git vendors.

Having looked briefly into it now, git-dit does look promising in its approach. I'd be interested to hear from someone who had actually used it and bumped up against the limitations: https://github.com/neithernut/git-dit/blob/master/doc/datamo...

There is git-appraise to fill that gap [1]. I am personally waiting for a federated "forge" for federating PRs across platforms, such as the one developed in [2]. Maybe via e-mail? [3].

[1]: https://github.com/google/git-appraise

[2]: https://github.com/forgefed/forgefed

[3]: https://drewdevault.com/2018/07/23/Git-is-already-distribute...

Pull requests could be done through email using the git format-patch, git send-email, and git am commands.

Merge the PR on github, pull to your local copy (now you're ahead of one of the urls of origin), push (and it should just push to the origin that's behind)

If you have any discrepencies in between them, you'll need to merge locally of course.

You could merge the feature branch into master (or whatever), resolve conflicts, commit, push and deploy.