The correct arrow length regardless of type of rest would be close to an inch under your draw length anyway. Being that the WB is a slight overdraw rest you could go even shorter if you wanted.

My question would be what do you think you are going to gain by shooting an arrow that is a few inches shorter? Your most significant change will be in spine, and I would be willing to bet if you are shooting carbons they are already stiff. If not shortening them might help. I would turn your poundage down first if you can to check and see if they shoot better. If they do you could cut them down and turn your weight back up.

Paul