Hi SG 16,
The P2713 rules are clarified in P2736 as applying only to UTF-8, UTF-16, and UTF-32. I think the "implementation-defined set of separator or non-printable characters" wording is a bit too restrictive to encompass allowing the UTF-8, etc. behaviour with other encodings of Unicode.
That said, I think we should move forward with both papers in their current state (and maybe tweak further later).
Thanks,
Hubert Tong