The VG-88 V2 upgrades are out there http://www.ebay.com/itm/Roland-VG-88-V2-Upgrade-Editors-Patches-More-/161603886691?hash=item25a0579e63:m:modRnLo3EH9WjlsmkwaNHBg
30% of those attempting the V2 firmware upgrade "bricked" their VG-88 - even VG-88 owners with BSEE electronic degrees !
Even today, Same high percentage of VG-88 owners continue to "brick" their VG-88 when attempting to perform the V2 update - ( it remains an extremely high risk procedure! )
Should you pursue this, must build the special (JIG PLUG)
use the Roland SMF "Player" https://www.roland.com/us/support/by_product/gr-20/updates_drivers/d9e54197-dd1d-4100-b56d-21e4c759f691/
*** Its crucial you use a high quality MIDI interface (Roland UM-ONE MKII) and send each of the eight *.mid SMF files that comprise the V2 firmware upgrade to the VG-88 via Roland SMF "Player"'s MIDI output "One at a time"
** Do not use the default mode of Roland SMF "Player" utility, as it defaults to the user pointing to the computer folder containing all *.mid SMF (VG-88 V2 update) files, then SMF "Player will rapidly auto increment and attempt to send all eight *.mid files sequentially via MIDI I/O connection to VG-88 being updated in one operation - without the individual *.mid SMF file checksum verification process!
That default mode of SMF player "auto-corrupts the VG-88 . Must Manually intervene and transmit each *.mid file one at a time, waiting for the checksum reply in between each *.mid file transmission