Don't take this the wrong way Rob but I would like to see your legs
in shorts, standing front on and side on (in your boots preferably). There is some prominent genu valgum particularly under load but why is not easy to spot. Is it, for example, pelvic asymetry, femoral rotation, tibial torsion, or excess pronation etc or all/none of these. I know alignment is more than having the knee over the toe and "one clinical sign a syndrome does not make" but it does look like your brain is trying hard to keep u balanced on your ski. Maybe some diligent drill work will alleviate it but i suspect not.
I would still encourage u to pull the free foot in toward the stance boot and narrow that stance. It won't solve the valgus stuff but it will decrease it's contribution. By the way I see improvements already so ingore my rambling if u wish.
I am assuming your aversion to put some pressure on the boot cuff is from reading Harald's commentary about "pushing plastic" perhaps (way back in Expert Skier 2 for example). I, myself thought it anathema to apply pressure to the cuff (and presumed erroneously that that was what he mean't) but until I did some work on fore/aft stance I would inevitably "crush" the boot anyway via excessive and inappropriate flexion trying to get forward over my feet. I think that Harald was seeking to promote being balanced in the boot and if you had to acheive it by pushing hard against the cuff then one would be fighting a losing battle. Sadly it took me couple of years to realise that (and some insightful instruction from Kiwi).
Proper fore/aft positioning now puts my feet behind the hips as best I can, promotes optimal posture and automatically pressures the boot cuff.
I would like to know about your feet in the boot/s and the possibility of some mechanism inhibiting pressure on the ball of said feet (foot/shin pain, footbeds etc) and creating some kind of defensive reflex. Maybe a Psychiatrist is in order
At 62 there are all sorts of ingrained movement patterns (good and bad) and trying to change them can seem like a serious insult to/on our senses. Keep it up because it is not easy at any age frankly and your progress is obvious.
This is a very intriguing exercise in movement analysis and I hope Max501 and yourself don't leave us stumbling around in the dark for too long.