Frank I think what you are talking about is the draw stop. And yes, moving that will shorten the draw. However, what it will not do is change your draw curve.

If you are going to change your draw, you are going to need a different cam module (I am pretty sure the TomKat works on that principle too).

If you don't change that module, you may well be anchoring before you hit what should be the back wall of the cam. Think of it as holding all the weight back at full draw. You effectively won't have any let off.