However, it is far from nonsense to state the rather obvious fact that in many (perhaps the majority) of cases, no such n-color profile is needed in order to exploit the full color range of a given multicolor printer.
Epson's X900 series of proofers, to cite a single example of what may be the world's most widely distributed proofing platform, use in addition to CMYK, Light C, Light M, Medium Black, Light Black, Very Light Black, Orange and Green.
Interestingly, though, I've never had any need to construct an 11 color profile. Even more interestingly, though my profile doesn't explicitly define green and orange, my orange and green cartridges continue to empty themselves. I wonder where all that ink is going.