With all due respect, allow me this rant:
RGB as a generator of colors and the inevitable gamut reduction of CMYK is something we simply must cope with. But that's not the real color matching problem. People seem to accept the reduced gamut of CMYK - as long as you never give them false hopw by showing then the RGB images.....
The problem comes forward in two ways:
1: Color calibration of the entire system, from digital photos/scanner to final CMYK PDF export to offset printer and the humidity that day and whether Jake had his hand properly on the ink throttle down at the web press.
2: The choice of process colors or spot colors applied in a color calibrated application set like Adobe's Creative Studio where the photos from Photoshop, the line art from Illustrator and the final color space of the layout controlled in InDesign. ArchiCAD is not one of these.
3: I addressed the "black" issue in my first book and will do so repeatedly in the second book. LightWorks renderings suffer as did ArchiCAD and almost all ray tracing renderings once converted to CMYK or printed on paper from RGB (secretly converted in the printer to CMYK) from
TOO MUCH BLACK
After a file is converted, yank the black channel back by one third and watch the luminosity of the rendering improve. The murkiness evaporates. Still not "Accurate." but much nicer to look at and prints cleaner, too.
You are right that few people are unrealistic enough to try to match colors across the RGB/CMYK threshold. I myself, as I convert my RGB files for the book layout watch in horror as wonderful purples and reds go greyish......
But the other unrealistic thing in trying to maintain color fidelity is that as illustrators, we are actually trying to reduce color range as we create the color story of the project. As soon as you deviate from pure white light in your renderings, creeping golden sunlight or North facing blue windows wil have your colors shifting ( and they might shit, too)
To answer then in detail - I only concern myself with the overall sense of a project and not that a client can lay a paint chip on my illustration and get a match.
I am reminded of a colleague, after painstakingly discussing a shade of Pantone ink blue with his unreasonable witch esthetician client then abandoned the job once he realized that her entire store color scheme would displease her because they didn't make sign vinyl in that blue. He sent her down to the sign company on her own to solve that one.
Dwight Atkinson