Tip Diameter
I just want to comment that it was a common conclusion when I was learning to play straight pool, the more tip on the ball led to more accuracy and less dramatic English. There were several very good shooters I knew who played with 14 mm shafts. Almost every cue I ordered 30-35 years ago had 13 1/4 or 13 1/8 mm shafts. There was even a poll in one of the Billiard Magazines then, listing the size of the shafts used by the Pros. Jim Rempe, who won more tournaments than anyone in the 1970's, thus the King James moniker, was using a 13.78 mm shaft. Very few, if any, were using a shaft with a diameter less than 13 mm.
Today, I am most comfortable with a 12 3/4 mm shaft.
But, now, with all of the technology, many players are down to shooting with 10 and 11 mm shafts.
I don't know, but when I am watching the Pros, it appears they are using shafts that have some girth or at least 12 1/2 mm, if not larger.
To me, using any shaft with such a small diameter would lead to certain inaccuracies or unwanted spin. But, maybe all these low deflection shafts don't produce maximum spin on the cue ball and throw on the object ball.
Call me old fashion, but I still like a shaft that gives a little spring and feels alive. Especially when I give it that hi inside to reverse the cue ball off the rail. "Hmmmm baby, how'd he hit it?"