Regarding GDAL versions compatible with SNAP, these are:
Windows: 2.1.x - 3.0.x
Linux: 2.0.x - 3.0.x
Mac: 2.0.x - 3.0.x
You can force SNAP to use the internal GDAL by:
or by manually updating the configuration (for users using SNAP with no GUI):
in .snap/etc/s2tbx.properties, add: s2tbx.dataio.gdal.installed=false