1.0 for monitor distance match at 0%.
1.245 for 1:1 360/cm match for 1x scope/pistols/smgs/shottys
1.39 for 1:1 360/cm match with lr/sniper/assault rifle ads without a scope.
Pick your poison. I just went with 1.245 since I use 1x scope the most anyways. I would have loved it though if we can set for each magnification so that I can mm 0% all other scopes aside the 1x.