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.
That may be harder to find. But complementing it with multiple platforms of differing political opinions may be a possible compromise.
Try the 64bit version. pi 3b should be compatible with it. Using the official flashing tool might fix any other issues.
You might need to be more specific, since there is a new wave of former redditors joining.As a former redditor, who joined ~2 years ago, it was very friendly and wholesome when I joined, but has been getting more toxic in recent times.
This might be an evolutionary war, since it's plausible, that detecting mosquitos led to less infestations and thereby to a higher survival rate.
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.