In reply to Francis Charlesworth:
Totally with He Ma on this.
4mm you will not notice. 2cm you might. Live with it.
I used to mount teles by some complicated formula to do with chord centre, boot length, ball of toe etc. That ended up with boot centre 35mm behind ski centre. Never liked it because it took a lot of concerted effort turning, gave for annoying tip diving skinning up and inevitably a destroyed knee.
Always go ski centre mark to boot centre (or as close as) for alpine downhill, alpine touring or telemark. Twin-tip Park skis will need even balance to successfully spin, so settings would be particular to rider and the ski.
Just noticed your post! "Binding mounting 4mm higher than the other"
Does that mean one binding is 4mm further forward than the other or 4mm higher off the surface?
I just mounted bindings to a pair of skis in the dark out the back of my van in the Queyras Valley. How some numbskull with a jig, correct drill bits and fully equipped workshop cannot do it, I can only wonder? It's not exactly Rocker Science now is it?
Post edited at 19:58