OK, I am probably one of those tire experts that is being referred to above.
First: "Class C" refers to vehicles, not tires. There is more or less a correlation between the 2, but it is possible for a Class C RV to have smallish medium truck tires instead of LT (light Truck) tires.
To my knowledge, no one makes an LT tire specifically geared to RV usage. There are some LT tires that are marketed as "Commercial", and what they mean is they wear pretty well, but at the expense of traction and soft ride.
And while I am not a rubber chemist, I really doubt that so called RV tires are really much different than regular medium truck tires as far as rubber compounding is concerned. The things that can be done to improve the life of rubber (as in how long before the rubber degrades) are expensive and suffer from the law of diminishing returns - that is: a little is good, a lot is only a little better than that.