The undercut edge of the kerf caused by the CW swirl should be on the metal you don't want and the straight(er) kerf edge should be on the metal you do want.
So if you want the square, cut round it CW but if you want the square hole then cut round it CCW.
i.e. the kerf (which is always in the bit you don't want) should allways be to the left of the bit you do want with respect to the direction of travel. (if that makes sense
)
That said, I don't think this is why your kerf
changes in angle. I reckon it's more likely to be explained by the paragraph "Irregular bevel (positive and negative bevel on the same piece" a tad lower down in your article.
(I'm assuming you're using THC ?)