The outsides of the tires will usually be the heavy wear point. When they get thru all of the grooves and leave you with slick tires, the insides will still look nearly new. So you just try to judge the wear and flip them before they get worn too far. It's the same on my RV-14 as it is on my RV-10, and I think it's due to the way the gear hangs and sags when you take the weight off the plane in flight. As you touch down the gear will have the tires tilted outwards as they hit, until they squat enough once you are planted. I'm sure most of the wear takes place at the instant of touchdown, not once you are rolling out with the full weight on the gear. It's just a fact of life on the RV's that you'll wear the outsides first. If one side wears faster than the other, it could be alignment, could be the way you were braking, could be dragging brakes, could be the above mentioned sticky pistons. It's up to you to verify if they are dragging or not, which is easy if you jack the wheel off the ground and spin it. You can probably also hear it as you push the plane into the hangar.
BTW, I have been liking how the Desser High Performance Retreads wear. They seem to be a beefy tire. Not as beefy as monster retreads would be, but any added thickness just gives more landings.