ive been detuning for about 10 years now, and have had really good luck with not pulling edges out (breaks still happen.) what i do is grab a file and go like a bastard from about 6 inches in front of the toe piece to 6 inches behind the heel piece. the more you round em off with a good file, the longer the edge will last on rails. if you have the patience and dont need to shred turns on icy groomers, round em off as much as you can stand. this will for sure make park ski edges last longer. BUT!!! you are rounding off the most critical part of the edge for making turns, so this WILL affect how the ski holds a turn/edge. so use your judgement on the ratio of turns to park you ride at