2018 Silverado Wheel and Tire Upgrade

Meep.... These are E-Load rated tires. I'm running 80psi in the rears, 60psi in the front.

I bought the MT because I take this truck through some stuff and now that I'm driving my car everywhere, the truck will mostly sit until I need a truck.... which for me mostly means pulling a trailer or putting 2 tons of material in the bed. I'm hoping I didn't make a mistake with these tires.

I loved the KO2's. But I was willing to experience these KM3's. Time will tell. I did read on several forums that the tires should stiffen up over time.
With your use case, I don’t think you’ve made a mistake. The rubber is still soft and will firm up with a few heat cycles. I don’t get the feeling you’re the type to hot dog the truck and get yourself into trouble. Worst case, you use them through their sweet spot and in a few years change them again. With your occasional use, they will age out before they wear out.