That's an interesting idea. You'd think less support would make it hurt more.
In your case I'm not sure, in my case it worked, two different things really. The thing is, since my leg was snapped in half (compound fracture and all) there was extensive tendon and muscle damage, I guess having your lower leg swinging around by the meat does that
I think with the softer boots there is less resistance to flex that doesn't work my lower leg/ankle near as hard. Have you tried any inserts to cushion the impacts? They also make wedges designed to reduce heel lift, might give those a shot. Obviously I'm not a Dr. I'm a construction guy so the only "real" advise I can legally dispense is "Duct tape that bad boy up and git r done"
Other then that I'd say see a real Doc.