I just noticed a smart entities tutorial in PDF format in the downloads section of the DataCAD website ( https://www.datacad.com/download/frame.htm ). Glancing over it, it doesn't seem to go into a lot of detail over the wall, door, and window type managers (doesn't seem to explain how to create 2D or 3D symbols to use with doors and windows, for example), however, it seems to cover the basics pretty well.
"No other success can compensate for failure in the home." - David O. McKay