Those are the kind of CNC kept in isolated rooms, and covered in gold foil to reflect heat. No humans allowed during the measurement cycle.
No, good thermal management with a chiller, active thermal compensation, and glass scales make um precision on that scale reasonable. 10-100x better? Sure, you’re getting into machines where the room to keep them happy is significantly more expensive that the machine…
The location makes access extremely challenging. It requires 3 hours of hiking, assuming you are fit, and borderline technical mountaineering once you get close to the site. The lower parts of the canyon are also under tens of meters of ice most of the year, which creates a separate set of safety issues. When these mountains were prospected in the 1920s, it would have been underneath a deep permanent snow field. I've visited some of the old gold mines in the area for calibration and this deposit appears substantially larger than those.
The discovery was accidental. I was looking for a waterfall I had seen on satellite imagery in the backcountry and came across an enormous chunk of molybdenite[1] while climbing across granite scree. I made several trips to find the source of the molybdenite higher up the mountains, which I never did, but while searching for that I localized a bunch of other beautiful sulfide/oxide mineral specimens to the above canyon. It gives me a great excuse to explore parts of the mountains no one has been into before.
[0] https://en.wikipedia.org/wiki/Bornite
[1] https://en.wikipedia.org/wiki/Molybdenite