draft-newman-mime-textpara defines a MIME type 'text/paragraph' which can be used over suitable CTEs just like text/plain.
...and I think it was premature for Chris Newman to withdraw it.
As for draft-gellens-format, I believe its attempts to handle >-quoted text compromise it, mainly because of the various ways people quote text. I think if we go that route, we should specify a complete markup language of *bold*, _italic_, - bullets, etc., with strict semantics for what any given sequence of octets means.
But if >-quote handling were stripped out, draft-gellens-format might work for general email: