I previously reviewed -17 with only two minor issues, one about "Domain Registrar" and the other about the IANA instructions.

Thank you for fixing up the IANA instructions.

On the issue of "Domain Registrar" and more broadly on the very frequent usage of "domain" itself, I still think it would be useful if the Terminology section called out these terms. While "domain" is obviously a general term, many of us will have a cognitive bias toward thinking that this is somehow related to the domain names in the DNS.  This is especially relevant with the term "Domain Registrar", and it was initially mental overhead for me on my first read on the document.  

I don't think you have to spend a lot of words on the matter, but I still think it would be an improvement to have Terminology define "Domain" and "Domain Registrar" as they apply to the document.  "Domain" is defined in RFC 8995, referenced, but "Domain Registrar" is not.

That said, I don't think this is a substantial enough comment to further hold up what is otherwise a solid document.  But if you're doing to rev a -20 for any other reasons ...