Yes, I remember that rule, but wasn't it used for OBS/Zero Reader type instruments, so you could tell (if you missed the passage) whether you'd reached the radial yet?
I teach on HSI (no FMS) type aircraft, and whether you set "Proper" or "Reciprocal" in the window, the Beam Bar assumes its correct spatial position, either to left or right of you.
Have a good think before shooting me down, because I was involved in quite a heated discussion of this some time ago (can't be bothered to post a link) and I have a simulator in which I can confirm my assertions.