Lots of discussion of this upthread.
Back on snow, I focused on this a bit, passively, to see whether it was happening or not. I found that past some depth, it was just happening. I didn’t feel that it would add much to try to do this proactively. But I guess if a skier were somehow blocking this movement *and* getting to edge angles where it should kick in, it could help to drill it actively.
To me "inside knee to outside shoulder" seems to mean to have some tension in the leg adduction muscles of the inside leg while being in an angulated position.
Inside ski tipping is mostly a combination of rotation in the ankle in the opposite direction of the turn and rotation of the femur in the hip socket in the same direction as the turn. This moves the knee away from the shoulder, but it is possible to adduct at the same time. But the ROM is a lot less in the ankle than for the femur in the hip, so if trying to tip inside ski "to hard" or in an inappropriate way, not letting the feet limit it, then the skis will end up diverging. Loosing up a bit on the inside ski tipping focus and adding leg adduction focus instead, can keep the skis from diverging.
I have tried this focus lately on our little indoor ski hill after watching a video by the gellieman. I like it, feel it is working and easier to keep the skis from diverging into A-frame.
Taking the inside leg adduction too far will block tipping of both legs and it is going in a "more hip, less knee" direction. For me I often end up in an
A-framed position, with lots of outside knee angulation, flat inside ski and no hip angulation. So I feel "more hip, less knee" is an appropriate direction. Click on the A-framed link and imagine how the racer in the background has moved his inside knee toward the outside shoulder compared to the poor fellow in the front... ;-)