I don't know much about the Supra RAM expander, but if it's not local to the accelerator I'd imagine it'd be Zorro II RAM - hence very slow! If it were just running a 68000 it'd be fine, but your '030 would never be able to get fast enough access over the Zorro II bus to get any decent speed, I imagine. Best bet is to get another 030 accelerator - I use an Apollo 2030 in my A1500 - which has SIMM slots. If your 030 is using Zorro II RAM you'll be lucky to get more than about A1200 (unexpanded) speeds despite the 030.
But then I could be wrong.
