Caster is effected if the front only is raised or lowered, the same if the rear is raised or lowered, in this case the front dropping decreases caster.
The pic of my Challenger in my avatar shows that the rear is lower because of the excess weight in the rear and that increased the positive caster making my steering even lighter, raising the rear as some people do decreases caster making the steering heavier.
I agree the Challengers need more positive caster for straight line stability, off set upper bushes help and so do after market upper control arms which have more caster built into the design of them.