Hi!
It would be really nice if we could start having *.flatpakref files[1] hosted at an official place at gnome.org. For example, it would be nice if we had the flatpakref file for gnome-builder 3.22 hosted at:
https://download.gnome.org/sources/gnome-builder/3.22/
I don't know the exact details in terms of what is required to do this and how this would work. I'm told there is a script located at https://git.gnome.org/browse/sysadmin-bin which is doing the groundwork for populating download.gnome.org. Perhaps this is something you can help with sorting out? :-)