It's a tire quality, and not necessarily a pressure issue. A decent tire should have a reasonable (more than 30% minimum) safety margin for inflation pressure. Inflating a 110psi rated tire to 120psi should not damage the tire. Also, the usual mode of failure is for the tire to blow off the rim, not for a ply to fail causing this kind of twisting.
It is possible that the tire's structure is getting damaged by impact with road hazards while at ultra high pressure.
1.2k miles is very short for tire life, but at $10.00 per 1.2k for a nice light tire, this might actually be a better bargain on a per mile basis.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.