I installed the 97 about 12 or 13 years ago and only had one issue with it about 7 years ago, but that was due to sitting for an extended period and upon startup a rusted piston ring caused the piston to be yanked free and a small part of the piston to be left on the cylinder wall.
Photos were posted of it back then.
Was able to reuse cylinder after cleanup and a good hone.
I talked with Bill at Bore Tech about a little divot in the wall down low in the cylinder and he said it was not an issue, it was usable, but the digit was not caused by the piston being yanked, it was in a different spot.