When I first saw this video, I kept waiting for the punch line.........I thought it was supposed to be a joke. Correct me if I'm wrong but aiming based on the size of your tip seems to me to be a most precarious approach.
The perspective of your tip size when aiming a 2 ft shot is significantly different than using that same approach to sight a 6 ft shot. In fact if I could view an object ball 20 ft away, my cue tip could completely obscure the entire object ball leaving no perspective relative to tip size. It's like holding up your palm to obscure the Sun....an object over 1MM times the size of the Earth. Distance plays a factor.
Mathamatically speaking, it seems that there is a specific distance that would correlate to your tip size and as long as all your shots were close to that distance, you could be fairly accurate; however, as is always the case with mathmatics...if you change the variables...you change the results.
Set up a shot that's 6 inches away and set up a shot that's 6 feet away and then see if this approach is consistent. That's the real test! Make sure your mental programming does'nt intervene to skew the results.