As long as you tune your bow and don't change the position of the slight cant I don't believe that it is going to matter at all. The level device that was metioned in the topic will keep at cant at the same position. It is not a requirement to hold your bow at an exact 90 degree angle. Not everybody's hand is the exact same shape, and for some holding at the 90 angle is not comfortable. For those that do hold it at an uncomfortable 90 degree angle torquing could be a factor.