The possibility of enrolling ROM keys would be great. It will still
be a PITA, just another administrative task in the best case and a real PITA if anything goes wrong, and it sometimes will.

Is there any slightest chance of buying hardware for Ubuntu (was it Ubuntu that made their own hardware requirements?) and somehow getting Fedora bootable by their keys? Not that it really sounds like a viable option for many reasons (like actually obtaining a needed hardware with the Ubuntu keys)