Even if there was a specific spot to aim for....It may IMO be a deterrent....I also think IMO...no matter what aiming system you are using there is a variable of subliminal adjustment....a GB center spot may not be visually what is best for someone.....
I find that I want any GB aiming aid out of the way as soon as possible....I feel it is only good for demonstration purposes and not a tool for developing ones stroke....
Example....I made a GB 3 line converter. Sometimes it is hard to tell is this a 1/4 ball shot or edge of ball shot....or even off the ball shot....You may be just not seeing it that day......I made this GB 3 line converter to show which line you are using...
View attachment 748299View attachment 748300
The GB center cut out is about the size of the tip of your cue....you can place it there and extend the line of the cue to show which shot line you are on....
Here is where it gets goofy.....If I focus my aim on the GB center (clearly marked) my pocketing is dismal....If I convert it to one of the 3-line locations my pocketing improves.....If I then remove the GB converter and use my own guesstimate of GB center and extension to the shot line on the OB....I pocket more shots.
I fully believe my visual subconscious makes any fine tune adjustments to the shot line.
So...IMO....GB or external devices should only be used for demonstration purposes to develop an awareness or ability to measure out where the GB center should be....and then converted to a aim point, contact point, vertical line point, overlap, shadow or whatever else you aim at to pocket the ball....Even using GB center (I feel) you will make some subliminal adjustments.....If there is no actual mark there from a device that you did not pick on your own.
Add to that.....the sharper the cut....the more subliminal fine tune input we are using as the precision necessary to pocket a cut shot goes up as the cut gets sharper........IMO
Sweet little tool!