All of the instructional data available for adjusting a tech camera for focus is biased towards finding focus at infinity. This, for sure, is the starting point. The adjustment process becomes more accurate by using longer lenses (100mm and beyond) but even that is limiting - the DOF is just too deep for an accurate focus adjustment.
The shimming range for infinity adjustment can keep an intended target in focus easily within a 0.03mm deviation. When I used my 150mm lens I found that my target remained in focus with shims ranging in thickness from 0.10 to 0.13 - in fact I probably could have taken that to further extremes but didn't (it was 100 degrees that day). I could see where the focus line in the foreground moved within the shim range but my intended infinity target was always in focus.
I found that after setting the infinity macro adjustment that focus adjustments could be fine tuned with the use of LensAlign and a Leica Disto D5 and, for Alpa users, HPF rings. The process is very simple and, to me, very accurate although it is very important to align the camera and the Lens Align tool properly. I measured my distance from the sensor plane to the LensAlign with the Disto and set my HPF distance to match (this happened to be around 6.5 feet for my 150mm). I started with my infinity shim range which added 0.10 to 0.13 shims to achieve infinity focus. My first shim adjustment which added 0.10mm to the standard Alpa shim resulted in a slightly back focused target. When adding shims to equal 0.13mm the focus shifted to slight front focus. All of this is very easy to see on the target at 100% pixels. The closest to dead on was achieved by adding a total of 0.11 shims. So, even though I had a range of 0.10 to 0.13 shim thickness that resulted in accurate infinity focus I was able to set focus more accurately for closer distances with the aid of LensAlign.
All of this applies to using a Disto and HPF rings but could also be applied to a Cambo if enough helical distance markings are available. Live view will eliminate the need for this but live view isn't always easy to use and is a big time battery dis-charger. Regardless infinity focus, at a minimum, has to be set.
Just thought I would pass this on to anyone who might be interested.