Thanks for the good answers.
The liner laces up so fit is nice and snug. The footbed is great. Not a custom orthotic, but better than Superfeet.
I follow the distinction between canting and cuff alignment. Kind of like how people call Titanal "titanium" when it is actually an aluminum alloy.
Anyway, it seems like the question is really about matching the geometry of my leg-foot. My bootfitter talked about how he would determine that and sounds pretty straightforward for someone with experience. I may have him do that next fall.
It seems to me that it is as much about arch support and pronation as the angle of my tibia.
PRONATION:I mentioned that these boots are better than my previous. It might be the superior footbed has as much to do with it as cuff alignment. In the new boots, if I was going in a straight line and I concentrated on supinating slightly that foot (which would approximate neutral), I could track a nice stable perfectly straight line, which was never possible before. Previously, that foot would want to naturally rail on the inner edge ever so slightly and would give me a subtle lateral wobble in that ski. I never wanted to ski straight because I could compensate for all this when the ski was on edge.
ANGLE: In support of the tibia angle is the fact that, in my previous boot, the tongue on that foot always rubbed the inner edge of the shin a little. Not enough to make a blister normally, but enough that I felt it after skiing. I take that to mean that the boot cuff and tibia rode at slightly different angles.
The bottom line I think is that it will be worth it to get all this measured next fall. I know there are exercises that can help with pronation and I plan to work on that this summer.