3 phase and main board versus add on board - can you use two main boards?

[exup]

I have 3 phase in Australia and accidentally only ordered the 1 main board, I see I need a second expansion board to get good readings. As a friend of mine is not using his kit as we purchased together, can I use a second main board (in the same way as an expansion board) by jumpering the wires across as its not stackalbe or will it have features that conflict?

Both boards are same version V1.4 rev 1