For DETAILS, most of the output is UTF-8, while for NOTATION*, there's some non-valid UTF-8 binary data mixed in. We've had some cases where Python scripts assume all of status-fd's output is valid UTF-8 and then they fail to decode it.
Would it be possible to always escape the remaining data (>=0x80) for NOTATION* for status-fd?
The question is who shall correct the wrong encoding of notation data (assuming it is flagged as human readable). Escaping is a solution but needs a lot of extra bytes.
In you case, is that marked as human readable ?
That's a good question. Looking at https://datatracker.ietf.org/doc/draft-koch-librepgp/, it doesn't really specify what encoding is used for "human-readable" notation, so I'd personally lean towards encoding it to stay on the safe side. Unless I'm mistaken, status-fd will only be used locally, so escaping overhead should not be a problem.
In our case, it's not marked as human readable.