About the only thing you know for sure is the TV manufacturers match the tires to the vehicle's suspension and advertised performance.
If a less expensive tire would meet their performance claims, they would use it. If a more expensive tire would give them an advertising edge over their competitors, they would add them in a heartbeat.
I cannot say that I recall a truck manufacturer offering a "sweet" ride, they all seem fixated on gonzo power, performance and capacity.
If increasing the tire load range, tire size or construction could provide a significant improvment they would have done so.
Does upgrading the tire increase the load bearing capacity of the tire? Yes, does it increase the load bearing capacity of the TV? I doubt it.