Digital BW, The Print

I'm wondering whether anyone (Lyson, MIS, etc) makes a B&W inkset for the 7 
color ultrachromes that looks like this:

position (1): glossy black
position (2): matte black
positions (3)-(7): 5 shades of black ink (or 4 shades plus a glossy overcoating 
used when printing on glossy)

It seems fairly logicial, given that many people use only 4 shades of gray ink 
for B&W currently (right?  isn't there where the term "quadtone B&W printing" 
comes from?).  Why not maximize the use of the additional ink positions in the 
7 color ultrachrome printers?

I know that initial reports are that the UT2 inkset will work on both matte and 
glossy paper.  But that's not available or at least not widely available yet.

Here's my other hypothetical for a 3rd pty ink manufacturer: just make one "tri-
color gray" cartridge, like HP does.  Then you just substitute this new cartridge 
with multiple levels of gray for the Epson black.  When printing full color, it just 
uses one of the blacks in that cartridge; when printing B&W, it uses all 3.

Thoughts?  (yes, special software would likely be required to implement 
either)