Thanks. I tested parsing a UTF-8 Concordance DAT file using csv-check. It doesn't work.
I don't understand your explanation of why there is a reference to the Unicode character with code point U+00FE in the Text::CSV_XS documentation. Why that character? I suspect only Tux, the maintainer of the module, can explain the mysterious reference to it.
The documentation is ambiguous with regard to whether or not Text::CSV_XS can parse CSV records that use multi-byte metacharacters. It says it "may or may not work as expected," and it also explicitly states that U+00FE, which is a multi-byte character (the two bytes \xC3\xBE in UTF-8), "will be allowed as a quote character." It's this very ambiguity that is the basis of my inquiry here.