One of the advantages Polaris enjoys over Can-am in the CVT department is pulley diameter, and the distance between clutch centers. The larger secondary pulley/sheave diameter affords the clutch more leverage at the bottom end, or off the line. Add to that ,the increased distance between the primary and secondary pulleys on the Polaris, and the result is a longer drive belt. This translates to less overall belt wear and heat build per mile driven because the work being done by the longer belt, at any given point in the belt, will be less than that of a shorter belt, by the same proportions of the difference in surface area of the two belts. I know, it's a mouthful, but it's the only way I can explain it.
The jest of it is that the longer Polaris drive belts simply offers more surface area than the shorter Can-am ones. The belt is in contact with the pulleys for a shorter period of time, per mile driven, than the Can-am belts, therefore, minimizing the wear the belt sees.
Your Right about the belt length for sure. Its like the SR1 car guys and if they run to short of a chain on them the chain just over heats and dies.
The Can Am guys have been out all summer long testing in the heat of Glamis and from what I have heard was only a couple of Belt issues so it sounds like the clutching is working and cooling out good.