I'm sorry, I'm not criticizing the method, but I have never understood the point in pre-dulling the razor. I suppose I might if I didn't use a microscope to assess my bevel progression.

Regardless, you're going to have to assess whether or not you've got the bevel set. That's the hallmark, critical, make it or break it, here we go decision point. Aside from geometry, the bevel would also widen if you are using so much pressure that you're flexing the blade. If the bevel is set, you need to lighten up on the pressure and move on up the progression, even if that progression is just along one of the coticule paths. If the bevel is not set, then you might want to put on a layer of tape or two to finish it.