The way some people "break-in" engines takes for ever, and they can even end up glazing the rings before the take a seat.
When you have a brand new engine on a dyno you can seat the rings very quick.
I buy / dyno a couple brand new crate engines (not 2 strokes) every year and put them on the dyno, run them at 1/2 load at 3500 rpm until engine temp is at 190*. Then we make full, wide open throttle pulls. They will make MAX hp in less then 6 pulls, most of the time its 3-4 pulls.
Polaris uses very hard rings that take more runs than the others to seat. Sleds aren't as prone to glazing like bikes due to the more constant and heavier loads.