I’ve just been looking at the binding, I can see how the adjustment works and the scale underneath is linear i.e. it’s about 10mm long. It’s as near centre on one as I can tell by eye but the other ski I’d say it’s about one or even two mm further back.
I’d be looking at moving it 5mm, same boot size but the boot length is different, the Garmont endorphin, megaride and radium are 317, 320 and 325 for the same mondopoint 28. I would assume, with no data at all, that the boot length of a Garmont outrider is 320 at mondo 28. Lou has a size chart on his site but I think the outrider isn’t a US boot so it’s not listed