Digital BW, The Print

I currently use a 1290 with the Cone Piezotone ink set driven by QTR. It works beautifully, 
but I miss the tonality control and the ability to print on both glossy and matte papers.

The problem is the 1290 has only 6 ink positions, so it is not possible to have the full UT2 
set with both Photo Black and Ebony Black, as is possible in 2100.

In printrs with 4 ink positions, only black, 2 shades of grey and blue toner is used.

My idea would be to use only the blue toner, not the light blue, and to use both black inks. 
It is mechanically possible with the CFS.

My reasonning is that with QTR I should be able to control the ink usage so that I could 
create profiles for matte papers and others for matte papers.

Is full tonality control possible with only the blue toner ? Or would the light blue be a 
better option ?