Sorry...lots of distractions right now and didn't make it clear in previous post
The OP is going to play with tire PSI and even tire size/types/etc
Point is that the PSI a very large component in this...even more important than or just as important as the class of tire. Discussions all the time of half ton'ers looking to go from "P" class to higher "LT" class, but many do NOT weigh the PSI as high in that effort
The tire images show how PSI can cause a tire to over heat and destroy itself.
Hopefully not the case with the OP, but the point is that the tires had too much sidewall flex and higher PSI will reduce that. Not a cure all, but a component of the possible solution
Once or over a series of over heating cycles...tire material will harden and not be as resilient as before...to create an ever higher heating cycle. This is NOT a snap or instant thing, but over time
An example is that the new era of tires needs to be 'broken in' or 'cured' over a few hundred/thousand miles. Complaints of wiggle, softness or squirrelly handling that goes away after it is broken it...that is the material hardening