Does HPy have any clear guidance or assistance for their users to keep it up to date?
not right now, because we are still somewhat in alpha mode and sometimes we redesign the API and/or break compatibility. But the plan is of course to stabilize at some point.
I think it can be done with clear communication from the HPy project (and us when we endorse it) that they will *never* break compatibility and it's *always* safe (and indeed, essential) for their users to use the latest version. But that's a big commitment that I can't sign them up for.
I think this will be doable once HPy is mature enough, and I also agree that any kind of official endorsement from CPython and/or PSF will help a lot the adoption of HPy itself.