One of the most diffcult concepts for newer riders to accept is that the steeper the terrain the more forward you need to be to initiate the turn. It is the last thing a person wants to do on an intimidating steep pitch but the must learn to trust this movement as it is the only way to get the board to make the turn in time to not loose control.
Then, once they finally get this concept, it becomes horribly difficult to get them to shift way aft for turn completion. You cannot ride steep terrain in a static stance; you must get as dynamic as you have the physical ability to do.
I found this quite interesting as it relates to my own experience.
My first time on snow started with a private lesson that apart from an initial practice learning how the board turns on a flatish beginner slope, started straight on a blue run. I had no previous understanding of how to snowboard.
We did cover falling leaf with the emphasis being very much on edge control, getting a feel for peddling (BASI) and board control. By the very end of the lesson I had linked turns but not with much confidence.
After the lesson (having already done the run twice I went straight back up and did it on my own. 2 hours after first strapping into a board and was doing a blue run on my own, I was so stoked (that was my goal for the week not the first day!) But
I pretty much did just did the whole thing falling leaf (went back to my comfort zone). What I remember noticing at the time was that i really started to get a feel for the edges during this run. I took a lot of confidence from being able to control the board well and stop safely. I feel like it was actually a very positive experience and by most peoples standards I've progressed quite fast after that. I've always credited spending that extra time doing falling leaf as a contributing factor in how quickly I progressed.
one issue I had at the start (and still occasionally have a tendency to do) was get in the back seat during turns (especially turning to healside). Not to the point where I'd fall but enough to pick up speed get out of shape and reinforce my fear of leaning forward down the hill. Overcoming that was pretty much the single most challenging aspect of learning as I recall. So I would say my experience reinforces what you say.
Since then I have done a falling leaf a couple of times when helping a novice. But at the same time I made it an exercise for myself by seeing how smooth and controlled I could make the pattern. I'm not sure if there is any real value in doing this but I did find it quite satisfying to be able to do it as smoothly as my instructor had demonstrated on my first day which I suspect is just the perfectionist coming out in me