the whole point of tall lower ball joints is to help with bumpsteer, correct some geometry issues, and to help in the negative camber gain of the sustpension. with three inch coils, you dont have enough suspension travel to encounter much bumpsteer, and are already into negative camber gain territory due to the control arm angles.
so, yes, the tall lower ball joint will help.
will it be noticible: probably not.
is it worth it? your call.
PP is producing tall lowers at about 60-75 days out, mine are already on order.
i will tell you that with teh 3 inch coild, my tall upper ball joint and UB machine UCA's were very good handling and predictable. worked well.
michael