Good write-up and ask if you do a lot of slow maneuvering on pavement ? and some noodling for thought over the never ending ST tire debates
How level is your setup ? Meaning does both or all axles share evenly...or nose down will have the front axle take more...and if nose high, the rear axle will take more
Have always thought that low speed maneuvering, on pavement contorts the tire carcass and the plys of both tread & sidewall, over time, begins to separate and/or are weakened where the cords lose rubber adhesion
Also wonder if single axle trailer have similar number or percentages of ST tire blow outs. As when they maneuver on pavement, the tires do NOT contort. They just pivot like the TV's steer tires would with power steering