I also wheel with a lot of jeeps and have seen how the coil spring design is somewhat unique in that it allows the top of the coil spring to come off it's seat to gain a little more flex. So I modified my bronco to do something similar.
These are about 8" long:

Installed in place of the spring retainer:

Flexed out with high lift:

Bushings at their max:

Phase 2.0 will be all new arms with JJ's and hiems! Hope that comes late winter early spring.
J.D.