An observation from another oldie …
In a former life, I used a variety of CAD/CAM packages that integrated the creation of geometry with CNC operations. When you “drilled” a hole in a material, you created it by specifying the drill diameter and length, the spindle speed desired, the feed rate into and back out of the hole as well as an optional “pick” rate. The CAD part of the software showed the hole that was formed (including the cone at the bottom of a blind hole), and the CAM portion would output the “G” commands to actually drill the hole with a 3-axis mill (or other). At the time, this was the Holy Grail of the design-to-part-in-hand process.
Today, CAD and CAM have become more decoupled from each other. If you can design a part in 3D and tessellate it into an ordered mesh of triangles, it can then be 3D printed in a wide variety of materials that don’t care where a hole came from. Or if it’s round or oval or if it curves through the part. This separation of the design and manufacturing processes has resulted in products like SketchUp that allow a designer to easily create the geometry they desire without worrying too much about how it’s going to be made.
You can “build” almost anything in SketchUp using the basic tools and some patience. If the tools are not enough, you can add extensions (or plugins) for more specific operations (or write your own). When you’re finally ready to give birth to your creation, you can render it or plot it or 3D print it as desired.
IMHO, SketchUp rocks