I recognize that at 1.5 or 2 rotor diameters that ground effect is negligible enough to be ignored, but as for the definition for the charts, I would have thought that "out of ground effect" is when you are not in ground effect whereas "in ground effect" is a published skid/wheel height.
Effectively, out of ground effect becomes the most power you would ever require in a zero wind hover for the weight & DA.
Whether you define it at 1.5 rotor diameters or 15 rotor diameters, as long as the power advantages of being in ground effect aren't realized then you have OGE.
N'est-ce pas?