After all, variable-contrast paper relies on both blue and green light to form the image.
I used to print Cibachromes and also used an RGB additive head, thus getting optimum results from the enlarger system.
Did that really improve the quality of the prints? I don't know, since I had no CMY head or non-APO lenses for comparison.
Yet I was sufficiently confident of the advantage that I spent a whole bunch of my own money on the system. The prints look great.