It is insanely quick with OneCNC to program off of 2d drawings. Plus you can import all your BC drawings easily. Not to mention dimension the drawing, the hole wizard. Depending on your print, in 2D you don't need to draw/show the thickness of the part in most cases. Just a flat drawing is all you need, you don't even need to use arcs i.e. circles to illustrate drill holes, only points are required, the hole wizard will sort out the dimensions of the holes from your input when you go to post your code. I could provide some simple examples if it would help.