I had STM on my secondary and a STM movable sheave on my primary (1100 turbo) and my bushing went out on my secondary after it had been gone thru and I did send it to STM and they said that was no good and for 750.00 i could buy another one.
I now have a 2017 turbo and before I bought it I questioned a lot of people and did speak to 2 people from STM and was told that they do not recommend running there clutches any higher than 8500 (new 3 cyl. engines like to run 88 to 9000)so I bought the Pro4 primary and secondary and have been very pleased with them and now have 2000 miles on them with no problems and my belt temps went from 160 to 190 with factory clutches to 125 to 140 with the pro4s. I do have a TD max 17 tune that I have ran ran since day 1.
Hope this helps