Does anyone have any experience with dislocation cones? Are they really helpfull or only for extreme suspension setups?

My set up is as follows:

Discovery 1
Detroit Rear locker
Full Ironman suspension Kit (40mm Lift)
30mm Spring Spacers
Rear sway bar removed

Will dislocation cones in the rear add any value? I am not sure the above setup requires them, or will articulate enough to dislodge a spring.

I guess the one day a spring does dislodge you wish you had this fairly in expensive item