Moving the stop one mark will not change much. As you move it toward the "S", let off will be less. Toward the "L" increases let off. The valley will get narrower closer to the "S", and wider toward the "L". Draw length changes, but to a small degree. There are optimum settings with each module re: stop setting. Experiment with stop setting and see if the module is the correct one or if you need a different module to get the set up you like.