Based on these results, it sounds to me like you really just want to narrow your stance a bit by moving your back foot forward. If a board is too stiff, you can always make it feel softer by narrowing up your stance. The bias on your Bomber is effectively doing this already.
Your photos also do a great deal to illustrate what is really happening in these systems. The bomber binding has a much smaller footprint or contact area than the Nidecker binding in this photo. The Bomber binding is definitely going to allow the board to bend more naturally as a result. The Nidecker binding has a bigger footprint and more of the leverage from your boot can, as a result, be transfered to the board. This enables you to bend or manipulate the board more than with the Bomber binding. The easiest way of accomplishing the same goal with the Bomber is to narrow your stance a bit. If it feels too narrow, just reduce your cants.