> I am wondering if the odds of it working with MOS
> will be better if flashed to G5 or to PC bios?

All I can say about this is what I wrote in comment #18. Maybe someone else can give a recommendation here.

> Perhaps MOS can boot with the MacPro bios?

With cards without PPC ROM, MorphOS needs AtomBIOS, which those cards don't have AFAIK. "MacPro bios" seems to be yet another type of BIOS/ROM.