So I followed Option B above

X130.51 mm vs 130


Y
109.4 vs 110



Z
39.75 vs 40

So they are all pretty good.

In my opening post, I measured in X a difference of 0.34 mm over 30mm, so 1.13 % deviation
My X calibration measures above deviate by 0.51 over 130mm which is 0.4% only.

Maybe something else is not right ?
Belts are tight, i cannot move the print head in any direction when printer is on.