Putting a closed-source application on Flathub is such a pain. Users of our app even request Flatpak support aggressively [0]. Yet uploading pre-built binaries, which is common for most package managers, isn't supported out of the box by Flathub. A direct upload option would simplify so many things...
Flathub does allow the 'build' to download and unpack a pre-built tarball. This is obviously not as convenient as directly uploading it, but some of those enthusiastic users might be happy to get the manifest set up for you, and then updating for new versions should be simple.
(And sorry about the pushy ones. I hope they're few and far between.)
[0] https://github.com/riok/Kreya/issues/64#issuecomment-1837278...