Patches and discussion for Ensoniq VFX family

Is there a chance that somebody somewhere have made an internally 
fitted cartridge board? I mean, instead of changing cartridges all the 
time, have anybody made an internal card-board with say 4 switchable 
cartridges for direct access to 256 sounds at once (or the like), as 
was done on Yamhas DX7 by I-can't-remember-who? It looks like it would 
be possible somehow (looking at the schematics anyway). And talking 
schematics: Is it possible getting/bying a schematic specifically for 
the 21 Voice board, or is the cartridge connector the same as on the 
VFX schematic?

Hope this makes sence :)

- Claus.