One problem which I've had working in this space is the difficulty of naming specific shapes --- worked up a list in my current project:

https://github.com/WillAdams/gcodepreview/blob/main/gcodepre...

(should be section 3.8.1.1 on pg. 97, not sure, since I need to push up an update)

and I'd be glad of any comment or correction or point of improvement.