No quotes will be added, as your delimiter does not occur in the text value.
How does this feedback fit to previously provided information?
A) https://docs.basex.org/wiki/CSV_Module#Options “… Serialization: If the option is enabled, the value will be wrapped with quotes if it contains characters that might be treated as control characters. …”
B) https://mailman.uni-konstanz.de/pipermail/basex-talk/2022-April/017038.html “… The double quote is the text qualifier that’s used for serializing fields with spaces. …”
Another XQuery script example: declare option output:method "csv"; declare option output:csv "header=yes, quotes=yes, separator=|"; <csv> <record> <T3>line 1 line 2?</T3> <T4>line 3\nline 4?</T4> </record> </csv>
Test result: T3|T4 "line 1 line 2?"|line 3\nline 4?
Will any more clarification help here?
Regards, Markus