I think a lot of businesses offer protocol design as a service, but it usually isn’t marketed as such. Drug and treatment development is an exception, since protocol is a term of the trade.
Differs a lot from diplomatic protocol where the service is intelligent compliance, not design. This service is downstream, relatively speaking.
Zie Germans are on it – kinda – unfortunately this book was only published in German:
It’s also primarily focused on the history of diplomatic and governance protocols, so not as wide-ranging a study as we have going on here. But I translated it with some software help and found it to be informative!