It's really almost pointless.
Any competent cue maker can offset his taper bar do a gradual taper handle and still maintain a thick forearm.
The top of the handle has almost nothing to do with the thickness at the bottom to those who know how to do it .
The popular taper back in the days was some .835-.840" joint and 1.275" bottom on straight taper.
Along the years, some makers figured out how to make a handle with a gradual and slim taper . That way, when you hold the wrap section in the middle or the bottom, there wasn't as huge transition compared to the old school taper .
Nowadays, a lot of cue makers make the bottom of their cues around 1.250" or less. It makes the bottom of the handle at 1.200" or less.
I make mine around 1.180" to 1.190" and still maintain a thick forearm.
I have an Excel file of cue dimensions of different makers. My late mentor compiled it . I think factory cues can vary a lot . The file says Joss at the bottom of the handle is 30.92MM or 1.218".
Thank you for the informative post.