One of the problems I was having was not being able to get good information from Sketchup on relatively tiny arcs. I’m using the CNC to label various cabinet parts and the cabinet numbers need to be very small.
In this case Sketchup displayed the 88 correctly but only the top arc of the 8 showed up as an entity ArcCurve. Checking out the bottom arc it returned a negative length, an incorrect normal, incorrect last vertex and a negative end_angle. I could select the top arc, but when I tried to select the bottom arc only 2 edges selected.
I stumbled across a solution that works for me. The solution is to have the script put the geometry inside a group which is inside a group. Then explode the inner most group. As we know Sketchup transforms geometry during an explode and the geometry inherits the layer. Now I can select the bottom arc and Sketchup returns the proper information.