I use sans serif to type matrices (and bold italic for vectors), but unicode-math does not support sans-serif for math greek, which is impossible to type like \mathsf{\eta X \eta}.
For XITS, you can use ss02 to load the sans-serif version.
But STIX2 does not provide sans-serif version of math greek.
https://github.com/wspr/unicode-math/issues/620
I use sans serif to type matrices (and bold italic for vectors), but unicode-math does not support sans-serif for math greek, which is impossible to type like
\mathsf{\eta X \eta}.For XITS, you can use ss02 to load the sans-serif version.
But STIX2 does not provide sans-serif version of math greek.