Hi.
Hmm your GVP rom's version is old.
Last offical release from GVP is rev 4.15
Your 2091 have newer roms. Last roms from Commodore is 7.0
So.. I think (not sure) you will get bigger SCSI disk on
the 2091.
But you can get the 7.0 rom for the 2091 easy from ebay for a few bucks. The 4.15 rom's for your GVP is more rare.
But, as I remember there is only 1 rom chip on the GVP?