I like the skimpy miter saw approach; I made one, too. When I mitered/beveled my blade according to the various charts, I get the right angles. I didn’t realize that you can’t just measure the bevel angle on a face of a rectangle; when you also miter, that angle changes.
This wasn’t about how to make crown molding, but rather about showing how it is made, so now I’m happy and understand it all better. Thanks to both.