Those baseplate holes have sharp and ragged edges.
I agree, I wonder if the inner edges of those holes would cut the ADBV (as we've seen many Puro filters do). Guessing the purpose is to induce a rotation inside the can (outside the media)? I'm not sure I buy the idea behind that, since the pleats are vertical and not angled in the direction of rotation. DuckRyder, how is the can strength? Does it seem any thicker or stronger than a standard Ultra? That has always been one of the Ultra's (few) weaknesses, along with paint/Sure Grip flaking.