Revision 0 are Phase 5 made BPPC cards
Revision 2 - DCE made BPPC cards, or Phase 5 made cards that went back to DCE for logic-chipset firmware upgrade to revision 2
I am not sure that there were any Phase 5 made revision 2 cards, unless upgraded to revision 2 by DCE.
This type of a firmware upgrade is different to the regular, downloadable firmware upgrade which a user can perform by themselves. It requires special equipment available unfortunatelly only at DCE.
There were no revision 1 BPPC cards.
Grex1200 according to my personal tests works flawlessly with revision 2 cards, and with revision 0 cards so and so, or not at all. My current revision 0 BPPC 060/240/SCSI card works fine with Grex1200, however an occasional crash here and there happens, which can be annoying. Another revision 2 BPPC card of mine has no problems or crashes whatsoever with the same Grex1200 busboard used.
Anyways, that's as much as I know about the subject, through personal experience, testing etc. :-)
EDIT: I've corrected an error in my explanation