I have one installed. I adjust the firewall adjuster (it won't work with the OEM quadrant in place) with the inspection cover off and the engine idling in neutral (all 4 wheels on jack stands). I adjust so the TOB just stops spinning. It's easy to tell if you peer into the inspection port with a flashlight. If your TOB is loud enough, you can hear it when it stops spinning.
If you want your TOB to spin all of the time, then you don't need the spring. I am of the opinion that the more the TOB spins, the faster it will wear out. So I chose to have my TOB spin only when the clutch is depressed.
My issue is since I have gone to an rxt and maximum motorsports clutch cable, quadrant and fire wall adjuster, when I'm cruising my clutch pedal rattles and if I barely touch it with my foot and It stops. I've adjusted the firewall adjuster to stop this and It basically just raises the clutch release to an uncomfortable spot. I figured this little bit of tension from the ldc mod would act like my foot.