Not sure what you mean by chain of events but it does sound like you may have misunderstood some of what we have said. For example, certainly the recruitment of core muscles can contribute simultaneously to the act of tipping your skis from the feet up. In many biomechanical movements, particularly when we do not have an external surface to press against for action-reaction; we push body parts against each other or pull them away from each other, in order to create desired movement that would not be possible otherwise. So do we engage the core in some fashion in order to pull the tibia down and out away from it in order to tip the skis from the feet up? I'd say there must be some combination of things that contributes to tipping those feet first and we have not at all ever said that the feet somehow isolate themselves while everything else is passive until made active in sequence. You are either presenting a red herring or not reading our words carefully enough chad.
It seems rather self evident that our whole body is used for many movements which SEEM isolated. In terms of creating edge angles in a state of balance, it matters a lot how those resulting movements take place, which is why the focus on the feet. Movements can definitely be isolated, even when they involve coordinated muscle activations in other places
I am sure I am not reading clearly enough. The feet first, I believe that is what I have understood. The feet first under a well organized body in balance using some combination of muscle synergies to achieve that balance. Am I getting it yet?
All I have been trying to convey is that the ankle movement and control that is so critical is as much a part of the motor engram/program of the efforts we use to maintain that balance with, as the rest of the body is to the firing at the ankle. if there is organization that needs to be learned from the bottom/up it would suggest that the same learning would be important for the top/down. As you said, there is still the ability to isolate specific joint control within a synergy pattern. The reality of our motor control is that the intention matters, the synergies will be different, the organization of my body will be different with each intention. That will have some impact on my ankle, and if being able to maximize its function is the main goal in skiing it would suggest a person learn as much about how they feel from all directions. Thats probably stupid though. Just for future reference, muscles can't push.