For the issue with AI files, it’s similar to what it was with DXF files. We have automatic optimization being applied when a design is imported because in nearly all cases this is ideal. I can reduce the allowed error thresholds, or possibly make it user configurable.
Having said that, I have to ask - Is this a real problem, or an imagined one? The circles you show in this image are less than 0.05mm in size, which is generally smaller than the dot produced by a laser with relatively few exceptions, and the actual error in the shape is less than 0.0025mm. When you engrave this image, are you able to see the difference?