I agree with statement about the steering geometry. The electric assist needs to go also.I've been thinking about this problem and the so many people who report having it. This has to be a defect with the JL design. It appears that when there is little friction between the tires and the road, as the case may be with newer (and perhaps stiffer) tires that are inflated sufficiently to provide a smaller contact patch with the road, the Jeep steering geometry is not providing sufficient directional stability. That is the bottom line - the inherent directional stability of the steering system, regardless of tire friction.
As in my case, dropping the tire pressure to create a wider contact patch seems to improve stability, or perhaps just mask the natural instability of the Jeep. Perhaps as the tires ware out in the center they naturally create a wider contact patch even at higher pressures, which has the same end result. But this is just masking the problem - i.e. a band aid. The root problem is the poorly designed steering system and I'm not sure we can do anything about that. Not without spending a lot of money anyways.