Well for 'fun' I just finished auto fine-tuning all my AF lenses. I have Nikon, Tamron, Tokina and Sigma and they all were fine tuned - how fine that tuning was is really hard to judge.
This was the set up I chose - used the lid of my 'new' antique Kodak 1940's camera for a target - lots of contract. I used an LED trouble light to get good harsh light. Set this on a TV table and used a tripod set to the right height. Using a box allowed me to know that I was square on when I could not see any of the sides of the box. Not 100% 90° but I'm hoping that would be close enough.
i did find that if redid the calibration for some lenses each time the adjustment would be close (within one or maybe two points) but for others it came up with much wider range of adjustment values, do it once, get -12, then again get -8, then again get -15, then again - 9. So I'd do it til I got a value somewhere in the middle of the range of suggested adjustment values. A few lenses came in a zero adjustment needed, e.g. my Siggy 50mm which does not surprise as that lens is tack sharp, my 200-500 was also very close to zero (I think it came in at -1) and the closer to the O adjustment needed the less the range of suggestions. Some lenses went up to minus 20. I just completed this exercise and have not used any of the lenses yet to see if there is a real world difference.
BUT this exercise is going to cost me.
I now have
13 calibrated lenses listed on my D500 - can't have that. I must buy another AF lens.
I do have more lenses but they are not AF - I don't think you can use this system to calibrate a manual lens - correct me if I'm wrong on that.