Something the Sailmates organisation may plan to take care about in the long run.
OTOH, as I expect GitHub to still exist in 15 years, another approach would be to map the current use of the SailfishOS-OBS for the SailfishOS:Chum community repository to GitHub. I started to think about that when evaluating how to map Patchmanager’s Web Catalog to GitHub and I think this is feasible for both and not really hard. With a bit of pondering and planning this might turn out to be technically elegant approach, given that most of the sources are already hosted there. For example, webhooks would become obsolete, as one can use GitHub-internal triggers in GitHub actions instead. But to implement that properly will take time. The biggest drawback I see here is a political one: If GitHub ever decides to switch off CI runs, GitHub actions or severely limit the resources used for these in the “free tier / plan”, this becomes infeasible (currently it is “just slow”, but the limits are almost impossible to hit). But in the past, GitHub has been consistently heading in exactly the opposite direction to stay the biggest hoster of FLOSS and proprietary (in “private projects”) software sources.