Could very well be...doesn't sound like a weight & balance issue. In fact your TT is similar to mine weight-wise...I weigh about 8500 lbs with 1200 on the tongue, about 14%. Actually I need to get re-weighed since I added the storage box on the back.
If you are looking to buy don't rule out the Pro Pride...same basic design as the Hensley but with a few improvements like adjustable height hitch bar, etc. Hensley started this new company to market his improved design after his non-compete with Hensley Products ran out.
You could always do the 90-day trial and see if it fixes your ride issues. If you are saying that if you dial in the DC so that the ride in the truck is acceptable and then that produces sway, the HA should fix that issue.
I would also agree that the guy you spoke to at HA pulled those aerodynamic comments out of his poop chute.
