Blackhand
This is a genuine question. If you are running at or below 65% power what harm can you do? My C210 Flight Manual gives figures for running at peak EGT so Continental must think it acceptable.If I lean further power reduces and CHT's reduce.It seems to me leaning once below peak EGT is being kinder to your engine.How lean you chose to go seems to be a choice speed and CHTs
Cheers RA