Update

[Salz, Rich]

 >   I'd be opposed to this last option without IANA/IETF being on board. By doing so
    we are effectively no longer compliant with IETF TLS since we're using certain
    codepoints and version numbers to mean things that IETF/IANA have no visibility
    of, i.e. we would be doing exactly what Rich was worried about. I don't see
    IANA/IETF doing this anytime soon.
   
For the most part, getting IANA on board requires someone in authority email to tls-registry at iana.org asking for code points and pointing to their spec.