Not necessarily true. How old is your PSE? I had an old school PSE Polaris Express that shared the same cams with that years Firestorm that changed peak weight depending on draw length adjustments because of preloading limbs more to get certain cable position on the cams. This was the old school method of adjusting draw length by putting the cable in different slots on the cam.

With Sonic and Muzzy heads though, who cares? It is still plenty to kill any deer out there. It's way more important to have the correct draw length than it is to have an extra 5lbs.