The current wording in [charconv.syn] is confusing at a surface level, but this is purely an editorial problem:

... the implementation provides overloads for all cv-unqualified signed and unsigned integer types and char in lieu of integer-types

Firstly, the reader may ask whether this means:

• (signed and unsigned integer types) and char, or
• (signed and unsigned) (integer types and char)

In other words, does this include signed char and unsigned char, or does it include char? However, signed char and unsigned char are already signed/unsigned integer types, so mentioning char separately here would be totally redundant. Only the former interpretation is plausible to me.

Secondly, the reader may ask whether "cv-unqualified" applies to char as well, but this question is totally pointless since char is already cv-unqualified.

Overall, we can reduce mental complexity here by simply putting char in front. Each of these questions has a clear answer (which is why this edit is not normative), but it would be better if those questions were eliminated completely.