You've learned to have the ski change edges by letting your arms out, and having the boat pull your upper body from one side of the ski to the other.
I don't know if anyone caught it, but during the KOD webcast over this past weekend I heard a few comments from Larkin about how there's two ways to move- The upper body can stay in place while the ski moves, or the ski can stay in place while the upper body moves. (Larkin has this mastered)
We want the upper body to remain more quiet while the ski moves underneath us. To be able to do this we have to have the hips and the handle stay in the same relationship before and after we pass through centerline. If we pass through centerline and allow the inner elbow bones to detach from the lower sides of the body then the pull of the boat will be transferred from the core of the body up to the shoulders. Once the boat has some pull on the shoulders it will begin to tip the skier to the inside of the turn regardless of what the skier is trying to do. It's very hard to swing out as wide or turn the ski with level head and shoulders if your shoulders are getting pulled on by the boat.
The longer we can keep the pull of the boat concentrated on the core of the body rather than the shoulders the wider we can swing out into the turns, and the more freedom we'll have to turn in the style we want once we release the outside hand from the handle.