If there's one thing you can always count on in the Linux world it's that packaging can be a nightmare. The OBS Studio team are not happy with the Fedora folks due to Flatpak problems and threatened legal action.
IMO, same reason they have their own repo, which eventually feeds into Red Hat enterprise, to have a trustworthy, curated set of safe (ish) software that’s had eyeballs on it. A worthy enough goal, but that said, it applies a lot less to flatpaks. I personally used to remove theirs because I didn’t like having multiple sources, now I’m on Bazzite which ships with flathub.
IMO, same reason they have their own repo, which eventually feeds into Red Hat enterprise, to have a trustworthy, curated set of safe (ish) software that’s had eyeballs on it. A worthy enough goal, but that said, it applies a lot less to flatpaks. I personally used to remove theirs because I didn’t like having multiple sources, now I’m on Bazzite which ships with flathub.
This is pretty much how Ubuntu turned into the shitshow it is now.
I don’t see much of a reason to create a customized flatpak, since at this point you might as well just create a binary for dnf.