One more time,
Yes LT tires undergo far more rigorous testing than STs, if you want to believe that those tests are all inclusive, that is fine.
I believe if that were the case, then the tire companies would not have wasted their time creating an ST tire with stiffer side walls, a rolling not traction tread design, unique rubber compounds etc. That is their words not mine. It is a purpose built tire for a specific application, trailer usage.
I suspect that an Indy racing slick tire undergoes far more rigorous testing than an ST but I would not want to use it on my TT.
My choice it to use what the tire makers designed for trailer service, others are free to make their own decisions. Certainly in the last 9 pages all sides of the issue have been discussed and rehashed. At this point any more dialogue would be anticlimactic.
Take care and you folk have a good day.