You can also try some of the following custom display modes that I uploaded in another topic recently, as well as to modify the edge settings if you wish so. They all offer a substantially better performance than the “Monochrome” display mode, especially if it has sharper shadows.
Чертеж 5.ini (12.7 KB)
Toon.ini (12.7 KB)
Toon transparent.ini (12.8 KB)
@wim , I tried your shadow settings for the “Monochrome” display mode, but seems like they want to kill my Nvidia GTX 1660 Ti 6GB. 
After I set those shadows the way you recommend, the framerate is about 1 frame per second or lower.