Yes, I'm saying that when I print profile target I set the print driver to "Color Controls", with the Color Mode set to "Adobe RGB", Brightness=+1, Contrast=-1, and all of the color-specific sliders at -1 (got these settings from Julia Borg).
What I've found is that using these print settings to profile, not only do I get a larger gamut particularly in the shadows, but shadow detail also seem to be a bit better.
But how do you print the target from Photoshop? Attached AdobeRGB and print with colormanagement?
The problem with using additional color conversions in the printer driver is that it shifts the primary and secundary colors in the target RGB away from the output primaries. This may significantly hinder correct behavior definition for the profiling software.
Would you have profile plots available to help us see the differences in gamut your experiencing?
The problem with the dark, saturated greens is actually a problem in the blackpoint compensation algorithms. Following is a gamut plot for L = 14 of a 4000 on GMG paper:
As can be seen, the a & b axes cross exactly at the edge of gamut. Unfortunately on the green side of colors. The profiling software now has to redefine what it considers neutral to make perceptual matches. But you can imagine that the smallest shift in mapping can have a significant impact on the colorperception because your moving around neutral. Note that the darkest color has L = 5 or 6. Anything between L=14 and L=min does not have an equivalent for true neutral, and you can't really make greens.
The trick is to compensate the dark saturated greens to a lighter, saturated version. The profiling software may do this in the Perceptual table, or otherwise you may do this yourself with Photoshop. The difficult part is that the slightest corrections have a significant visual/perceptual impact in that color range.