Thanks Corentin for the paper. I hope this feedback helps the discussion.

With respect to the contents of multicharacter literals, the paper does not
give much motivation for disallowing numeric escape sequences which fit
within a single unsigned char. Also, the wording says "shall be a member of
the basic literal character set": this property of "being" is rather
ambiguous in terms of authorial intent regarding the treatment of UCNs,
etc. that designate members of the basic literal character set (a name for
something is usually not the same as the thing it names).

With respect to the new encodability restriction for strings, I believe
that unevaluated strings should not be treated the same way as strings that
need to be translated into a literal encoding. I think we may need to
advance P2361 ("Unevaluated strings") first.

-- HT