I don’t believe Sketchup produces vector files, so curves aren’t actually curves when you zoom in, they are stepped straight lines. Since the CNC can act with great precision, if you give it a circle composed of a large number of straight lines, you’ll get a “pointy” circle out of it.
That being said, I did run across a SketchUp plugin that helps create g-code. I’ve not used it myself (I am working through the process of learning Fusion 360 and have done a few CNC projects on it - but I prefer to do initial sketches and designs in SketchUp for the most part and then re-create the finished design in F360. Sketchup is really great for fast brainstorming). I’ll dig up the link for you…
I found this: "As far as a plug-in, SketchUcam is probably your best bet for a free option.
If you can afford it, V-Carve Pro can import Sketchup files and convert them to G-Code for your CNC. The drawback… It’s $699.00. I’ll be trying SketchUcam to see how accurate it is before investing in V-Carve Pro."
I didn’t know that about V-Carve Pro, intersting.
Here is the link: https://openbuilds.com/projectresources/sketchucam.1/