Tech info.
Polaris 115 belt size - 46.77" (l) x 1.46" (w)
Cat 048 belt size - 47" (l) x 1.453" (w)
So take about one turn out on the deflection adjuster and run the cat belt. Its damn near a 3 for 1 deal.
Also, just because a belt does not fall apart does not mean that it is still "good". Belt dust comes from somewhere. Your belt. It is continually getting skinnier. Sure, deflection can be adjusted, but are you also adjusting primary sheave clearance, Clarence? Probably not. That's the benefit of the $65 cat belt. Swap them out every 1000 miles since your on the 3 for 1 program, and the seat of your pants will appreciate it. 2000, 3000, 6000 miles on a belt is impressive for sure, but surely not "optimal".