Take a file and go to town. 45 that shit right off.
At least on skis you have 2 edges. Even if you have them detuned you still have twice the gripping power.
Also on skis the area you actually slide rails is so small compared to the size of your ski.
I can't think of one good reason why I wouldn't straight round my edges under the bindings and around that area.
Hell I only snowboard these days and I still have my edges round. I can't turn for shit but you don't really have that problem on skis.
I guess the only reason I wouldn't detune them is if I didn't hit rails. If you're actually going to hit rails detune them. If you want to detune them because that's what other people do then don't.
Nothing sucks more than shaving into a rail and dying because you hooked an edge.
Even massively more so if you're ever going to hit urbans, backyard shit... Generally most mountains have rails in prime condition, if they get burred, they get shaved down. IF you're going to hit pvc, aluminum, and other urban or backyard shit round them or die.
Good luck.