Since I very rarely find myself holding on the actual center of the bull I find that the dot helps quickly define the intersection of the cross hairs. I am blind in one eye and can't see out of the other so I need all the help I can get. Did I mention floaters ?? Fine CH are often lost in the floater haze whereas usually I can see the dot.
Correct.
I shoot a 1/8 dot also. But I do not always center it on the bull. I usually set the bull on the horizontal and rest it against the vertical , sometimes on the right side, sometimes on the left, and sometimes on the bottom,sometimes the the top. Whatever is working that day, am I the only one who does this ?. Take care, practice hard, shoot easy....