I was referring to "Flatpak [...] is currently only working as expected on x86_64" is ... if not false, then far too easy to misunderstand. Flatpak works just as well on aarch64 for (at least) hundreds of apps. The software that's not available on, e.g., flathub for aarch64 (but is available for x86_64) in most cases is not available (in compiled form) for aarch64 at all — because it is proprietary with vendors not caring about aarch64, or ... just is electron-based ;-}.
It's not Flatpak, it's the entire aarch64 software ecosystem that's lacking here. Stating "Linux on aarch64 has less available software than x86_64, which is especially so for proprietary software" would have been a far better statement.
Please correct me, but AFAIK, necessary configuration of flatpak (e.g., configuring remotes) depends more on the distribution than the architecture (as long as the architecture is supported at all, that is - so x86_64 or aarch64 AFAIK).
Sure? https://gitlab.com/postmarketOS/pmaports/-/merge_requests/4820 And does it hurt to mention differences in software support between x86_64 and aarch64? I would see your point if I had talked at length about Snaps. ;-)