Lower preassure on a E-Bladed cocker, doesnt really affect chops, if you are using the eye...its more for Mech Cockers. However, too high a preassure will blow your Cocking solenoid...also, its more efficient at lower preassure. You can add a low preassure Chamber it you wish...it replaces the gas nut, that holds the front block on and is a cylinder, that extends between the ram and so on, up teh middle. However...there is controversy as to whether they actually achieve much...Nexus cockers dont have them, that may be becasue they feel they dont work, or they wont fit between the pneumatics or a combination of both.
Sweetspot your regs...i have posted how to do it before, if you hit search.