Support Platform/SDK beta releases on flahub.org
It would be great if the GNOME platform pre-releases (e.g. 3.33.9x) were published as runtimes on Flathub, not as nightly builds (doing so would waste a lot of people's bandwith), but rather as once-off builds of the platform's 3.33.9x release set.
This would let GNOME apps publish their .9x releases as betas using Flathub's beta support, and also enable the platform getting some wider testing before being released.
I'm in the process of setting up a beta for Geary at the moment (geary#313), but the process is hampered by the fact that the 3.33.x platform and SDK runtimes aren't available on Flathub. Fortunately this time around there's no specific API the new release depends on but that could obviously change in the future.