Thanks for giving my filter a test. 
It occurs to me that calling it Auto White Balance is not really accurate, even though that was the intent. It colour enhancement that happens to get close to a white balanced image in many cases.
It is trying to maximise the number of hues in an image, so when an image naturally has very few hues it is going to produce unpleasant results.
However, in some cases, it produces nice results that probably did not look like the real scene. For example, this image from DPReview’s Nikon D5 review camera WB is probably most accurate but I prefer the hue variance version.
Edit: Also, with a standard whit balance picker you need pick a neutral grey, but with this method you need an area with a range of hues. I’ve found that peoples faces often have enough variation in hues to produce good results. So you ‘white balance’ without any neutral grey.