Yup! Some are better than others!

To my knowledge, all piston rings will rotate unless pinned. Especially in 2-strokes! If they didn't move what would be the point of pinning the ring? Because of this, there isn't much harm in taking apart a ringed engine as long as you don't stretch out the ring. If I'm not mistaken, the OS 50SX heli engine has a nickel plated cylinder just like their non-ringed airplane engines. This surface is very hard and, despite it's smoothness, doesn't require any scuffing or honing. A coarse scotchbright is usually all it takes to clean it up. After re-assembly one tank of fuel gets the ring back where it wants to be and you're ready to fly. At least that's been my experience.