This is an awesome write up, thank you for sharing. As someone with difficult feet, I often times find myself skiing in pain for most of the day. I've had a lot of work done on my boots but they are not perfect, but because they are only a couple of years old I'm hesitant to invest in another pair. I'm hoping that working on my form will help lessen the foot pain.
Can someone try to share when adding a heel lift is necessary? Should your heel never leave the bottom of your boot?
I'm reading into what you wrote a bit. I don't believe heel lifts are to take up the space in your boot so your heel can't leave the bottom. I have limited dorsiflexion so my dorsiflexion range of motion is shorter than the average. The heel lift lets me work in the range that is most beneficial to skiing (fully forward and back instead of 3/4th of the way there and back. Using my amateurish drawing below, if the black triangle is my foot and shin angle and the red line represents my max dorsiflexion, you can see that "IF" a heel lift was installed and my foot was seated on it (in the picture it is above it because I suck at making drawings), I would have the same range of motion, but the red line would be more forward. Try to picture the black triangle with the base of is sitting on the heel lift instead of hovering above it. The whole thing would tilt forward a couple degrees.
In "my" limited understanding of this craft, if your heel is coming up, it could be because your instep is too large, or the pocket for your heel is packed out or not a match for your foot. In my Langes, the heel hold is a like a vise! Maybe more like a bear trap. The grip it has on my achilles tendon is just this side of uncomfortable. Another day or two skiing and all will be good. I don't think I can get my heel off my insole without unbuckling my boots and I LOVE IT!
Heel should never leave the bottom of the boot. Right.
Boot fit can make this impossible to accomplish, if the volume or length of the boot is wrong for your foot.
Or Left