Just my humble opinion, I think improves on Depth Cue are necessary!
Since a started used this amaysing program called Sketchup, I notice that simple problem that never was resolved in SU/LO! The program has the Depth Cue tool, and I don´t see anybody using this tool. I think it´s because it´s not necessary, unless the authors do something about the improves on it, for example: the Depth Cue can be a tool that when you active and the camera view was selected on parallel projection, the line weights are becoming thinner as the distance of the drawing is the PLAN OF THE SCREEN, and not the CENTER OF SCREEN like it is actually.
Sorry about the english, and thanks for any person who answsers me!