Why do you insist on a different but functionally equivalent solution to the problem?
It's weird.
> Why do we tolerate the fact that GitHub doesn't let you say "approved for changes in `frontend/*`
That's literally what stacked PRs are adding.
> Why do you insist on a different but functionally equivalent solution to the problem?
Because it’s not functionally equivalent.
Stacked PR’S only facilitate easier reviews by forcing you to make the layers of the stack mergeable in chunks. It forces the “unit of review” to equal the “unit of integration”, which is completely unnecessary. It forces unfinished code into production to accommodate a broken review UX.
Maybe you want to land a subset of a change early, maybe you don’t, but wouldn’t it be nice to make that decision independently of worrying about the faults of your review tool?