Everything should get burnt at peak EGT, or anywhere LOP.
I can offer one data point: my engine got
rebuilt (Lyco SB569 crank swap) at ~700hrs, after ~650hrs of peak EGT operation 100% of the time (except climbs), and the only items which were outside
new limits were the exhaust valve stems (they were about 0.002" outside and still within
overhaul limits), and the cam followers. The engine was otherwise spotless.
Now, some 400hrs on, the compressions are all ~78/80.
I am not aware of anybody who has operated similarly (which is quite common among pilots of similar aircraft, though some operate nearer to 75% power whereas I fly low level at ~65%) and who has found anything different.
Turbo engines are a different thing; they seem to crack cylinders well before TBO no matter what one does
