I can't swear as to which edge Ken is referring to, but IMHO rounding the top and bottom edge of the square corners of the outer surface of the flange would improve the look and reduce the potential for a sharp square corner being a literal pain. Nothing drastic, just break the sharp/square corners. In looking at the photo of the shield, it shows some blending. Your treatment in the last drawing looks closer to what I envision you will wind up with. Looking good.

It ain't ignorance that does the most damage, it's knowing so derned much that ain't so! J. Billings