Pictures of holes? Unless you mean the ring landing of the pistons are "chipped" around the 1 o'clock position.
It has been said that the NA engines don't handle detonation as well as the SC engines. And the SIII doesn't handle it as well as the SII.
Also been said that KR over time will weaken piston and they can fail without seeing KR.
If and when you do this again, aim for 1* of KR max even in third gear. Even then, play it safe and aim for zero.
And don't tune around KR, adjust the pulley size or fix the mechanical issue causing it.
Should last longer, but there's always that chance.