The twisting of leaf springs is not rocket science. One of the reasons (beyond greater spring rate) for multi leaf springs sets is to eliminate spring twist. A greater arc in a spring will also eliminate spring twist somewhat, and that also is a reason for greater spring arc beyond just giving it more travel. Stack enough spring leafs and make them greater length leafs, and you will almost totally eliminate spring twist, but use a single leaf like some 70's F body cars had, and spring twist will be very noticeable.
Rubber bushings eliminate spring twist by allowing the bushing to do the work, rather than the spring. I've read what Herb Adams has written, and he's extremely knowledgeable on suspension, but I still disagree on use of poly bushings in the front eye, as I think it's just making the rubber bushing do the work, instead of the rest of the suspension.
The reason track/street cars use a disconnect on their anti roll systems is because they use such heavy systems that they wont work well on the street. Swaybars designed specifically for street use do not bind so much as to lift the rear wheel when cornering. A swaybar's whole design is based on binding, but the material used, and diameter will dictate how much it binds, and that's why they work well if sized correctly.