Dan,
I know what you printed in your OP, but ... just as a double-check ... was your destroyed tire "M&S" or "M&S2"?
I would have thought that Michelin was no longer making M&S tires and all inventories, everywhere, had been purged by the time your RV was built? Otherwise, why did Michelin introduce the new M&S2 design in the first place? If I'm right, I wonder why/how your 2011 RV still came with the M&S tires?
When my M&S tires needed replacing in 2011 I became aware of the new M&S2 tire and specifically directed the tire shop to NOT install the over-20-year-old-design M&S tire. The M&S2 uses some different materials in it's construction and I'm hoping that this fairly new design solves the aging problems that are occuring with the older M&S tire.