> I'm sure I'm wrong about some detail about some of the points above. Someone is likely to say "he could've just done this to solve problem 5(a)"

Yep, I'm going to do that!

> Work-in-progress commits towards addressing review feedback become visible as soon as the branch is pushed. This forces contributors to address all feedback in a single commit, or for reviewers to deal with partially-addressed feedback.

This point isn't really valid. It assumes that the contributor wants to push their new work addressing feedback to the remote as soon as they make each commit. That's OK, so do I (in case my laptop disappears or whatever). But, it takes 1 second to make a git branch, so you can just push your new commits there and then merge or cherry-pick onto the PR branch when you're ready.