First, I was replying to X-Re, and second, you are wrong, at least under the conditions I specified. When you use relative colorimetric rendering intent and black point compensation, the white point of the source color space is mapped to the white point of the destination device space, and the black point of the source space is mapped to the black point of the destination device space. Intermediate tones are mapped proportionally between the destination white and black points, so that a 20-step gray pattern will appear to have an even luminance interval between steps on the monitor and the output device. The distance between the white and black points will vary somewhat depending on the printer and paper type. Matte papers have less DR than glossy, so while a 20-step gray pattern printed on matte will have a smaller tonal interval between steps than one printed on glossy paper, both prints will exhibit even step-to-step tonal gradations from white to black if the printer is properly profiled. I've verified this behavior with an Epson 7600, Epson R1800, Canon S9000, a couple of color laser printers, as well as a few other third party vendors I had make prints for me at one time or another.
Granted, prints have less DR than a monitor display. But that certainly does not mean that one must set the black point of an image to RGB 15,15,15 to avoid shadow blocking. All it means is that prints may appear less contrasty than a monitor display. If you have to raise the black point to RGB 15,15,15 to avoid shadow blocking when using RelCol+BP compensation, either your printer profile is bad, or you're trying to print some really dark, saturated out-of-gamut colors. Period.