X-Rite eXact repeatability for samples where L* < 20 goes down. This issue is already a subject of dedicated research.  Deep black in the case of Textile C is reached by double-side printing which is rare.  

A 2 mm aperture makes this instrument NOT recommended for textiles.  In practice, the aperture for textiles should be 8+ mm. We used 2 mm eXact expecting this issue to show it by numbers.
Also, we see the same situation when unprinted Textile B is more homogenous than A (compared to i1Pro 3). 

We see that the dominant direction causes Textile B to be angle-sensitive (waves create a structure with visible dominant directions, light reflects not the same depending on the angle.) The annular ring is based on three points where the tungsten gas-filled lamps are located. Such a solution is partially angle-sensitive.

The third step is not arithmetic, but the logical sum of the first and second steps.  Based on previous results we know that we shouldn't use this instrument for textiles and any no-uniform, textured amples.