A way to include the actual commits of backupped PRs?

[Jackenmen]

I've noticed that taking a backup of PRs doesn't include their actual commits in the git repository backup.
Is there a way to do this already that I might be missing? If not, would you accept a PR adding such functionality (by including refs/pull/*/head in the things to fetch from remote), and do you have any preferences on what it should look like?