Very interesting. Thanks for posting. I did find myself thinking, "A guy who has skiied to the North Pole three times could probably look good with a pair of running shoes attached to 2"x4"s with a few wood screws", but still it was thought provoking.
If you don't have to bring speciality boots, bringing skiis (or snowshoes) only on an early-season PCT starts to look more appealing. A high-cut lightweight trail shoe would be up out of the snow most of the time.
Something we'd do in the ski shop 30 years ago was to mount adult bindings on kid's skis to do tricks on and go down really steep stuff with a lot of control. I wonder how that would work on X-C gear? What's the shortest, metal-edged ski you could have for Sierra snowfields? Maybe kid's 90 or 100 cm downhill skis with skins? You could climb up anything and come down anything. Except for not knowing what below you on a ungroomed snow field!