All they have to do is point to the underbody damage and say you abused the vehicle.
It sucks. But at the end of the day, these trucks are not intended to land on rocks. There is no way for you to determine the damage from the original hit didn't cause additional damage that caused the tranny...
You could be remove all the weights, from all the tires and take it back to the dealer... If the wheel comes back with the same amount of weight, there is your anwser....
Or take it to a reputable tire specific place....
I totally get that.
I think the majority of users won't notice changes in performance during normal use, they might at the limits of the suspension (hitting a speedbump at speed etc). But that probably wouldn't be more than huh, that settled differently. (2 or 3 cycles of suspension to settle...
I should note, I have a tremor, with the factory fox suspension and it is great.
If you buy the used set see how many miles are on them, and find someplace local that does rebuilds and get a quote. The Tremor fox suspension can be rebuilt, and should I suspect at similar intervals as standard...
Check out the @ShockSurplus youtube channel.
They have tons of information on valving and how the shocks perform in different situations. They have videos for most major brands that explain the valving differences. And different applications.
If I had stayed in Florida I would have loved a diesel truck. In my experience, diesel was much easier to find during the madness of Hurricanes... For that reason alone, I wanted a diesel truck.
IIf there was a diesel hybrid option, Jesus I would sell my left nut for that.