".. not created from pressure" ?... Wouldn't you need pressure to resist the turning force that is required by Sir Issac's elegant laws of motion? (No pressure would mean no turning).
The pressures in the left-right sinusoidal turning translate directly into the up-down virtual roller pressure that the skier would experience.
I described the inclined plane, and I described the change in effective slope. Certainly, if a skier was to travel over rollers then changes in pressure would need to be dealt with.
The skier encounters a hill of increasing pressure, followed by a downslope of decreasing pressure - at which point the skier can add some of his own drive to pump the turn.
If it was a bump - the skier would pop. On the lateral, the skier would not so much pop as shoot forwards (as in the 'accellerative turn' diagram diagram I cribbed from Brodie et. al.)
I don't think you need to contradict anything I wrote in order to add to the debate.
I don't have time to read past this post, so maybe it has already been dealt with, but the "virtual bump" exists in addition to any turning pressures required to cause you to turn. If you can visualize your tracks on the snow as railroad tracks, then take away the snow and imagine a roller coaster going along on those rails you will see there are turns and "bumps" that are sections of horizontal track between sections of descending tracks (much like the flights of stairs and stair landings you would get if you straightened the line).