I mean, isn't that how it should be though? Pick a scheme (preferrably not in the IANA registry), design something, figure out what works in practice, optionall

I mean, isn't that how it should be though? Pick a scheme (preferrably not in the IANA registry), design something, figure out what works in practice, optionally find it so nice that you'd like to share it with the world and make an RFC to register a new scheme. Rinse and repeat.