Nice idea, one that I will keep in mind. But the whole point was to have a single board.
I'm not sure what you mean by "simply install the diodes necessary". Did you mean resistors? My design started that way, but when I only included the holes for the needed resistors, it simplified the board.
It also allows me to include the one connector to the logic board, which has a matching 6 position on it. Less wires; one ribbon cable.
But the price is attractive... I feel a redesign is possible.