The question is, why are you not just merging them into main as you go? It's a bit of a smell when you "need" to merge branches into branches. It shows a lack of safety and ease in deployments, which is the real problem to solve IMO.
Because sometimes there are changes that need to land as all or nothing.
Stacked PR’s… don’t do that though? They’re just PR’s. You can merge just the first one in the stack, and now it’s not “all or nothing”. Reading the docs, I don’t see a way to signal that the PR’s must all merge together.
Because the most natural way of saying “these changes need to land atomically” is called a branch, and landing it atomically is called a “merge”. But I guess GH’s UI sucks for reviewing large changes, so we’re stuck having to make each change independently mergeable and pass tests (likely disabling dead-code lints, etc) just to work around this limitation. Sigh.
At least when I actually do want changes to be mergeable in a stack, I now have a better UX for having folks review them.