Hi David,
You like to ask "provocative" questions, to provoke thought, I mean! So I'll add to your question. When we look at the world with our own eyes, in color, presumably the lenses in our eyes are not perfectly achromatic either. Our brains probably use the color variation to enhance our perception of patterns and edges and textures etc... So perhaps if we could make a print using perfectly monochromatic light, perfectly focused, it would look less natural and lose information compared to the "micro-blur" in the gradation of tones caused by slight chromatic aberration? In other words, would this kind of sharpness be too much of a good thing at the expense of important contrast? Perception of sharpness is more than resolution... it's not obvious to me that a perfect monochromatic projection would appear sharper!