certainly not a 31L specific issue....
but my take on this issue is
the rear axle is mostly likely at capacity or even overloaded.
and it's likely that the tires have been run while under-inflated, and therefore overloaded even more, even if only occasionally....
In my estimation, this is generally the case for all the class c's approaching 30ft long or more...except maybe the super c's
and all four of my outside factory michelins were covered in little cracks....very much before the time they should have been...based on both age and miles...
when my 31L was new I took to gauging the tires every morning. A royal pain in the neck. I fought with the braided extenders from the factory for a while leaking and just generally hard to gauge and to air up....
finally took them off
then I struggled with getting at the inner valves....
eventually permanently removed the wheel simulators. Wish I'd done that day one!
and eventually I bought a TPMS, mine is a TST. Good piece of mind but not a total end to worries....
I did have a blowout once, and it wasn't the failure mode that the TPMS would have warned about.
I replaced the entire set at that time.
I have considered many times swapping out to the larger wheels...
https://ricksontruckwheels.com/wheels-ford-e350450.php
a few threads about them on the forum
I would have done it at the time of blowout, but on a trip, no time, etc...
so for now I've been just hyper vigilant about my replacement tires