yes you can move your nocking point to get the same results;but the movements are the opposite of the nock point movementto acheive your tune.If your D-loop is tied right your knots will not slip.Once you put it in the string in the location you want,put a closed needle nose plier inside the loop ,and while holding your other hand on the bowstring pull on the pliers to tighten the loop.For added insurance you can also tie stringserving or dental flossinside the loop(above each knot)to help keep it in its' place.