The big factor in wear is DIRT. The film thickness of any oil at operating temperatures will only be a few microns thick, but a bit of dust will exceed that thickness quite easily. Spend more time and money on better air filtration and less on oil and the piston/cylinder wear will be reduced.
A proper warm up also helps piston/cylinder wear. I remember reading the results that KTM did on their two-strokes. If they gave an air-cooled engine a 3 minute warm up before putting a load on it - it reduced the wear by 50%. On a water-cooled engine it was a 5 minute warm up to reduce the wear 50%. I start my saw, then put my gear on, by the time I get dressed and walk to where I'm cutting, the engine has warmed up.
Here's an easy way to determine if your oil film strength is adequate - check the rings and the top of the exhaust port. If you see some brown or blue spots on the rings, the film strength is inadequate and the rings have been touching down on the cylinder wall.
