(And listened again to the "Move your hips forward!" command from several coaches over and over)
I did a little homework and browsing around for some science on the physiology of proprioception and balance.
All you tech-heads may like this.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290100/#b3
"Skin receptors [in the soles of the feet] may therefore be able to detect not only the movement of the centre of pressure as it moves towards the boundaries of the base of support, but may also be able to initiate postural reflexes that promote a more stable standing position. (Do et al. 1990)."
So... not only does sensory/positional processing up in the brain happen from a much higher density of sensory information in the feet and lower limbs compared to the hips and torso --- there is evidence to suggest the existence and ability to further develop reflex arcs (basically, the sensory signals from the feet only enter the spinal cord, then directly activate motor neurons back out to key postural muscles, without traveling up to the brain for processing).
And traditional ski techniques still focus on "moving the hips forward," despite there being no muscles or muscle groups to make that happen.
Anyway, thought this was very interesting, and further confirmation to focus on the feet for fore/aft balance.