Uhhh, thank you so much for this in depth explanation. Your result is so fantastic, that I forgot about this technique. Even though I made a short tutorial about this as well… 
I am getting old.
But heavy decimation for the “outline object” was not possible in Nomad those days. The one I got the trick from used layer to adjust size of outline object, which is clever. Maybe you’ll find something useful for you as well, even though your 3D knowledge seems to be much more experienced than mine.
Thanks for those game screenshots. I never expected to see the outline technique in games where polycount is such an important thing. Very nice. I used to work with illustrate! an NPR renderer for 3Ds max ages ago. Super complicate, slow, but with nice results. Nothing for real-time, but I was after vector output those days.