The page I linked to was not about automatic AF fine tune (the D4S which the page is about, doesn't have that feature anyway).
If you use a 3D target then the phase measurement shows less clear peaks. The sensitive area of the individual focus points is also not necessarily accurately defined in the viewfinder and can include some sensitivity in a wider area than shown, so you might have two or three bars affecting the measurement.
However, what is good is that the lighting is bright, the distance is appropriate for your application, and there is high contrast.
Nikon warn against repeating patterns and against 3D subjects as focus targets, and you have both. That doesn't mean problems will automatically occur, but there is some risk. Of course, the risk can be mitigated by real-world testing and refinement.
