Well, yeah, that's what I am doing. One smaller board to handle flat and banked games, and another larger board to handle RAM and POKEY games. The >128K configurations are just a matter of adding new bank address lines, so it's a relatively trivial extension to make room for up to 1Mbyte.
Hmm, I didn't realize that was your original goal, although it seems that you have accomplished it. I thought you were trying to come up with a cheap & simple way to create >32K 7800 homebrews.
I'm just not going to experiment with someone else's radical ideas on new ways to do bank switching, that nobody even knows if they're going to work, and won't have anything to run on them anyhow. I have only about a jillion things of my own that I've been wanting to do for a long time, so I don't need any more stuff to do. I don't see a need for something between a GAL-based board and the CC2 right now, since I can do everything "standard" with a single GAL chip, and one or both of the Activision/Absolute bank switching modes if I cared enough to figure them out.
So anyhow, I started playing with Cadsoft Eagle on Sunday afternoon. I was up until 5AM making a board layout before I forced myself to go to bed. I even had to learn how to make a library object, and tore down the object for an 8-bit ISA card as a starting point.
Now I have a layout that looks correct, and it's only missing the D4 and D5 inputs to the GAL chip for 512Kbyte and 1Mbyte bank switch configurations. I'm probably just going to drop a couple of vias in strategic places and require a jumper wire or two for the really big configurations. After all, someone's got to create enough content to fill that much ROM first.
It was a pain in the butt to route, too, since it's so tight with both a 32-pin ROM and a 24-pin GAL chip. The large IC pads take up enough extra space that there's literally nowhere left to add any more wiring. I suppose I could use circle pads like on the Pixels Past boards to get room for a few more horizontal traces, but the vertical direction is totally crammed.