The noise I had was not from the launcher. Mine already has the Delrin launcher. It's the internal mechanism that's rattles.
If this is the case I would send the rest back. Put a sock over were the rest hits the riser. Then cock the rest and hit the front of the bow with your hand to set off the rest. I hear absolutely nothing. This is with a 3 year old model with a metal launcher. Not saying you are wrong, there just might be some reason for the noise.