I got absorbed by the site yesterday when I had the time. What they're doing seems excellent on all fronts. I think the 3rd leg of this stool is parental involvement; in the least that the atmosphere at home is conducive for the kids carrying out those things at home so they stick, because quite a bit is taught. Not in terms of "this piece, then that piece, then that piece" but "this skill, that skill, the other skill". (right up my alley)
I'm also reminded of what I was once told by a teacher in person: "Students must feel safe." How much is fear a hidden factor in music? Beyond the intentional old fashioned "nun rapping errant fingers with a ruler", there is the fear of making a mistake, looking bad in front of the teacher, sitting like a good little statue so as to be perfect. The stuffed animals I fussed about before, they are part of fun, non-threatening, and reassuring. I first worried about a factor of "posing for the camera" which we do see in demos, but the laughter seems genuine, spontaneous and relaxed.
In videos about legato (or slurs) the release is induced by plopping little stuffed animals on a playing hand, and the goal is to flip the critter to fall forward but not to the floor. That is a thing that will make you laugh, but also you're not self-conscious, fussing about your wrist and fingers - you're aiming at the flip and end up with free loose movement. There happens to be a little stuffed frog by the piano. Tried it. Frog loved it! 😃
The one thing I worried about is, if all teachers do the same thing, is there room for a good teacher creating a lesson geared to a given student, aiming for the same goals but altering the specifics? The other side of this is consistency. All teachers flip stuffed animals and such; if a teacher is sick or moves away it continues - and they can still apply the ideas their own way. In fact, there are a couple of videos about different student personalities, and gearing toward that.