First off, congratulations SnoKarver!
Seems we've gone off track here.
After some official exposure to PMTS(thanks Arcmiester, excellent clinic), I agree with the narrow stance concept as a teaching tool. However, speed and high edge angle require "loosening up" a bit.
Several years ago Aldo Radamus talked about "grouping" which he described as the effect you get when you corner a bicycle with the outside pedal down and the inside up. The feet are quite aways apart but not very far from the centerline(width of the bottom bracket). In skiing this produces a pretty wide stance during edge change as it would be inefficient to "narrow" then split again. Mind you, we're talking high speed and edge angles. I've also noticed after, watching HH and others ski with thier feet tight together, that it takes an "up" motion to get across the skis to change edges. This is an interruption of the constant flow of the center of mass towards the bottom of the hill.
In general, I like the approach and organization of PMTS. As with all "systems" you can't get hung up on one thing.(as many of us like to do) I've been using a lot of these things for a number of years(I've also been clinicing with Arc for a lot of years). You have to look at the whole package and not get "dogmatic" about it. I think it was SnoKarver, in another thread, who said "whatever helps my student to learn is what I'll teach". That's the way it should be.