If new directory scanning options are added, would it be possible to design them so that they, or rmtree(), can eventually implement the equivalent of rm --one-file-system?
Many dir-traversing UNIX utilities support --one-file-system, such as rm, du, find, rsync.
It prevents against accidentally traversing into mounts, which is a useful protection; almost as useful as the symlink attack protection provided by dir_fd based functions.
It’s implemented by comparing stat().st_dev.
But in Python this is not currently implementable, because deletion requires e.g. topdown=False in os.walk(), which then forbids filtering traversing into directories.