This draft violates many aspects of BCP56, and needs substantial revision to address that.

That's because it's tunnelling a protocol over HTTP semantics (primarily POST). Doing so prevents many benefits of using HTTP from being realised and may cause deployment issues.

I would recommend mapping the semantics of EPP more faithfully to HTTP -- e.g., <create> to PUT, <delete> to DELETE. This would be a substantially new version of EPP but would be much more integrated into the HTTP ecosystem. We can look for volunteers from the HTTP community to help with this direction if there's interest.

Failing that, if the authors wish to tunnel, they should do so using CONNECT rather than over HTTP semantics (such as POST).

The draft has other issues (including interoperability concerns) that I won't list here as the decision above needs to be made first.