I wonder if an edge finder would work.
I use an edge finder and it works great and is very accurate. I use the displayed DRO values to record the offsets.
Like Hood a height gage is used for setting tool height, and after the tool table is populated, I also refine the threading tool
offset.
The "trick" is to use Mach for measuring the offsets using a reference line (ie; the od and face of the edge finder), use mpg's to touch off to the edge finder, and use a different screen set to avoid the back and forth between screens. Also
the master tool concept is used.
Some where i have a write up of exactly how it's done.
RICH