I like it, but I feel like it is closer to a merge request message / merge / rebase commit message.
Generally I think it is good form to break down your stories so they match the scope of a reasonable merge request and name the branch [issue-id]-human_readable_text
Agreed. I can't imagine working on a feature branch and writing 50 of these for a moderately large change, just for those to be squashed. I mean, I can, but I don't think it's necessary.
I wish that github would stick multiple commit messages into the default pr body - if I have a single commit it'll prefill the pr body from its message, but have a series of commits it won't. Should use the same rules as it's default squash message IMO
GutHub support for reviewing multiple commits is basic (to be generous). The focus is all on the "PR" the entire diff and the description (that lives outside of git).
I think this is pretty harmful to having a useful git history and a conspiracy theorist would likely say that it is intentional lock-in.
Generally I think it is good form to break down your stories so they match the scope of a reasonable merge request and name the branch [issue-id]-human_readable_text