You have run into one of the things I hate about bow "tricks." My side of the story; I run the shop and at the shop no one discusses "tricks" with my customers in my presence. I'll order them out of the place. Customer wants to go "trick" his bow, fine, but not at the shop. I'm that serious. Running a shop you have a liability responsibility.
You want the perfect draw length? Then set your bow by the Martin manual, mods to desired draw length (that fits, not by the numbers), cams synced, draw stop set.
I take it that you are using a loop. This is fine just make loops of 3 or 4 different lengths, 1/4" difference to start. These can be shortened by melting the ends back. Try each loop length until overall draw length is best for you. Do not use a loop so short that it creates crush, squeezes the center serving or creates nock pinch. If a tad bit long, then play with the draw stop - this being advancing the draw stop. Don't move or change anything except the draw stop. Advancing the draw stop does four things, it shortens the bow's (1)draw length, (2)shortens the valley, (3) lessens letoff and (4) has the cables not lay entirely flat in the module groove flats. Your bow is still timed, synced and all, just that the draw stop is changing cam locations. Okay, it's no different than if you have the draw stop set short. Here, the cams will rotate so the modules will push the cables, both at the same time, before the draw stop hits, but the bow is still timed, synced and all.