Simple explanation. Go to the tech archives here, click on suspension, read bulletin 15. Doesn't matter if it's R&P or conventional steering, geometry needs to be correct. On R&P the inner socket joint can be considered the inner tie rod end. The wobble shown on Tig's car is not caused by bump steer. Many different theory's. Mine is the front track is narrower with the suspension in jounce. When the car comes down there is pressure trying to push the tires outward to reestablish normal track width. This pressure causes the wobble phenomenon. Not just Mopars, it happens on a lot of cars. Mines done it when the compression on the shocks was set very loose, tightening it seemed to correct the issue. For what it's worth mine has had the toe pattern corrected to zero through it's entire travel.
Doug