While toner-transferring and etching our game board "modules" something became obvious - though it's not something we'd thought of when designing our PCBs. The photo below shows our game board etched onto a piece of eurocard sized (160mm x 100mm) copper-clad board
While trimming to size, we realised that the bit cut off the bottom was almost exactly the right size for a single row of 4 playing squares (the printed module above shows a 2x4 grid of playing squares). It then occurred to us that there's no real reason why we couldn't create modules that were 1x4 instead of 2x4.
After all, the top row still has to be connected to the bottom row using a wire jumper/via even when they are drawn/etched on the same piece of board. So here's the new PCB layout for four playing squares at a time:
Since the spacing of the playing squares is 30mm (standard Blood Bowl size) the PCB is also 30mm high (with the playing squares pretty much in the middle of each "strip" of 1x4 squares).
If you want smaller playing squares, simply resize the whole PCB. The overall size will shrink to match the size of each playing square so they should still be able to be cut to size and placed side-by-side, without affecting the spacing between playing squares.
A little bit of multi-core wire or maybe even some gloopy solder should connect the two boards, edge-to-edge.