yr right, in my experience operating skydive aircraft, 470s and 520s, many, many thousands of hours, I never had a cracked cylinder. To be fair nearly all the engines were factory remans. Always carried power in the descent i.e. 2300 rpm 23" when down to certain height, straight in approach reducing power as required.
If people are cracking cylinders in skydive ops then they need to look at how they are managing the engine.