It's not just the pics, they've got a pretty good angle on them. They go from 0-25 and I've got them set at 15 degrees. With them at zero it was pretty hard to rock back on my heel edge. After watching the SA setup vid I figured I'd be better off with some angle. I could try a little less.
What's more important, boot perfectly centered, or balanced force for engaging both toe and heel edges?
OK, so I went to 10 degrees on the highbacks and rotated them back inline with the binding rather than the heel edge. Now my boot goes all the way in and the overhang is equal at ~1" heel and toe.
If I rotate my highbacks to line up with the heel edge, the outside edge contacts my boot first and keeps it from going all the way to the back of the heel cup. So, I know highback rotation is a contested subject. That said, centered boots with highbacks aligned with bindings or 1/4" off-set (toe side) with highbacks rotated inline with the heel edge?
Might just be the pix, but it looks like you've got a helluva sharp angle on your highbacks. If they're steeper than the natural angle of the boot, it will make it harder to get the heel all the way back.