That's something that troubles me greatly about this engine. I'm used to having 400 to 700 hour engines with zero to extremely minor light polishing of the piston skirts, and what there might be would be limited to the very bottom corners of the skirt. All the pistons still have all the original machine marks on them at 400 plus hours. The kind of tolerace issues in the 30 cost a lot of performce due to friction losses in areas where there should be no issue at all. Likely never develop any piston slap as the ring wears for sure, but you're wasting a lot of power in overcoming tolerance deficiencies. A lot like running an engine with a semi siezed bearing that can't float to overcome the friction. When the prop comes out of the flight phase of flight after the throttle back for a landing the engine could easily stop during the landing roll out.