Hi,
I'm pretty sure you can't get around the 6MB RAM limit with the Bridgeboard. The A2286 maps it's memory locations to that area of Zorro II space. You can however get a 68020 or higher accelerator board and it's 32Bit memory (usually Zorro III on the memory map) should not interefere with the Bridgeboard at all. You then might need to run the "Enforcer" program if I recall...
Good luck!
-G
