By any chance did you manage to get branch protection rules working neatly in this paradigm? Ideally I’d like any CI to be re-run as necessary and the branch to be automatically merged if review was approved and its base became master, but I never got a completely hands free setup working. Maybe a skill issue though.

Basically if I have five stacked PRs, and the newest four get an approval, I want everything to stay in place no merges. Then when the base (oldest) PR gets approved, I’d like the PRs to all get merged, separately , one after the other, without further interaction from me.

Does GitHub’s merge queue implementation support that?

Gitlab’s does when you have merge queues set up. I’m not sure about GitHub, we didn’t have that kind of setup at the last place I worked.