Well, perhaps you're right in that you can't increase the wheel rate by pulling the center of the tire contact patch closer to the body then the hub face.
Because even if you do so, you can't really shorten the LCA length. However, if the center of the tire contact patch is normally outside of the hub face, I would think that decreasing the track width would increase wheel rate....though we're probably talking minutely.
But I was just thinking that if I bolted a long, long rod to my hub (sticking out perpendicular to the car's natural direction of travel) and then grabbed that bar at the end, I'd have much more lever arm. If a wheel was then mounted on the end of that bar, the wheel rate would be really low.
Sorry, I didn't get a change to jump on my home computer last night. I got home from work pretty late and basically went right to bed. I'll
hopefully work a more normal day today...