Got the meter and the tripod and I compared between direct contact vs around 5 inches away.
Besides slight luminance changes which is somewhat normal, absolutely no difference in measurements between the meter on direct contact for 2 hours and the kuro burning it, and the meter cold at a distance.
On the gamma side unfortunately the low end can't be set differently without screwing up green in the midrance IRE.
On my panel gamma 0 = around 2.15, gamma -1 = around 2.20 and gamma -2 around 2.25/2.30, I chose the last one.
Some findings about the CMS, gathered from various d-nice posts and trials :
G C and B mainly affect the low end, so they can be used to tweak the greyscale on the very low end.
As a side effect of using the Green CMS, it will rotate your red and blue colors in one way if pushed right (red will slowly go up through the entire greyscale, and blue will go down), and the opposite if pushed left. Used with the RGB highs/lows it can open some tweak perspectives.
Yellow can be used 1 or 2 clicks to tame the red channel on the middle up side, if needed.
The other ones I haven't figured a logical pattern that would explain their use.
Anyway I've got the best greyscale I ever had, unfortunately I found no combination that would better the 5 and 10% clics without having worse results overall, so I'll live with it. Raising brightess to +2 would cut dEuv by half, but it raises idle luminance, and it's not an option.
Blue falls a bit on the high end because of ABL imho, I used ted's lightspace disk with 11% patterns (AVS APL small patterns give very similar results, a bit different, but not much at all).
Colorchecker SG averages 0.6dE now.
Still not as good as the d-nice reports though, I don't know how he manages to get there... something I'll never have, his experience...
This is with brightness +1 :
This with brightness +2 (obviously better, but screws the blacks) :
And Controlcal settings for that :