You can use -G1 to see where the tags are coming from, and -a to extract duplicate tags if they exist.
Just specifying -gpslatitude will extract either the
EXIF GPS version or the XMP-exif version, whichever exists.
If both exist, it will extract the last one found in the file,
which should be the XMP-exif version for JPEG images
written according to the EXIF spec.
When writing, you only need to write gpslatitude
and all versions will be updated, and the tag is added to
EXIF if it doesn't already exist there. Or you can write a
specific version with exif:gpslatitude or
xmp:gpslatitude. This is all explained
in the application documentation.