Hey Max...the movement that I'm describing is not what I see illustrated in the video you posted.
That skier in the video is UPweighting to transition. In the video Liam posted and what I've seen John do (and I have practiced) is where the skis have constant contact with the snow, dead flat using a powerful lower body rotation. (think windshield wiper)
Your idea of practicing pivot skips on groomed with the skis flat is spot on. Do this while focusing on picking up the transition speed that each pole touch starts is a good way to learning how to apply in 3D terrain.
Don't think I'd use a blocking pole plant in this situation at all...in my experience, it's very rapid fire touches with the pole plants and get-em out of the way.
When I've see JC do a series of 5 or 6 of these in a row, his arms are to the side and the poles hanging straight down, no wrist or swinging pole movement.... it's just touch touch touch touch....with each touch the skis swing right then left then right then left......for this movement, it's so freakn' fast and amazing to watch and more so when I could link 3 or 4 together.
G