> can we now boot an X5000 with the two cards and OS4 doesnt choke
> on having two?

Yes, but OS4 still requires its card in the primary slot, else there wouldn't have been any problem as the MorphOS card has always worked in the primary slot and OS4 would have simply used its card in the secondary slot (which it cannot, at least with the primary slot in use).
As is known from running dual-boot OS4/Linux on X5000, OS4 running on the primary card isn't disturbed by a secondary card.