This is a very well written and detailed document.

I have only one concern, which I believe should be addressed before moving this document forward:

I found the rational and specific details on what this document "Updates" from three previous RFCs to be lacking, and confusing.

I recommend an "Updates from RFC XYZ" section in which there is a textual explanation and ideally Old/New specifics on how this document updates previous RFCs. At least, something more inline with current thinking as per https://www.ietf.org/mail-archive/web/ietf/current/msg109106.html

Thanks,

Carlos Pignataro.