Related to this topic, I was testing out the machine with some hole boring operations using Fusion. This results in a helix tool path for each hole. A helix is a series of circles in XY while Z is moving linearly. At first it worked fine for holes of about 20 mm. When I reduced the size of the hole to about 19.4 mm or lower I started to get missed steps after about 3 or 4 circles in a row in a hole. You hear the machine shutter when this happens. I was using the controller to do the arc calculations with the circular interpolation box checked in post processing and max deviation setting of 0.05 mm.
My assumption is the controller was not keeping up. To resolve this I had success with either lowering the feed rate giving the controller more time to do the calculations or unchecking the circle interpolation box forcing the post processor to do the calculations with a tolerance of .002 mm. The latter option results in bigger g-code files but faster run times.
Bottom line, with the stock controller, if you leave the circle interpolation box checked and are doing small holes always test first to see if you get missed steps and take appropriate action.