Nope there is no way around the 8 MB limit. Either you switch off the A2630 Ram (not recommendet) or you limit the Ram on the GVP to 4 MB.
The two existing A2630 Ram expansions DKB 2632 and Access32 are a way to have more Ram with a humble A2630 but usually prices for those boards are so high (as they are collectables) that it is cheaper to get an other accelerator alltogether like a Blizzard 2040 that allows for more Ram on the board itself.