schjfI may be wrong (i've never owned on3ps) But on their website it said factory detuned
gnar_whalYes, only on the tip and tail contact points, not underfoot. Their only ski that is factory detuned underfoot is the filthy rich.
gnar_whalIf your hitting rails then yes, you definitely should.
1. Take file lightly over the underfoot of the ski, and about 3 inches in front of the heel piece and 3 inches behind the tailpiece
2. Remove burs with gummy stone
Just did this with my Kartels, works great