QTR-Quadtone RIP

I am currently working on a curve using an Epson 1400 w/ UT14 inks on Ilford Galerie 
Gold Fibre Silk, and I am in the process of trying to maximize the dmax.  The inksets are 
as follows:

ink 1 K = Eboni Black
ink 2 C = Cool PK
ink 3 M = Warm PK
ink 4 Y = GLOP
ink 5 LC = Dilute Cool PK
ink 6 LM = Dilute Warm PK

Here is my dilemma, I selected a ink limit visually at 40% (2.27) without the aid of the 
densitometer readings, but the dmax actually occurs at about 70% (2.39) according to the 
densitometer readings.  Since this is a glossy paper, the Eboni in the K position is not 
used.  So this is all done with the Photo Black inks in the C, M, LC, and LM positions.  I 
printed out the inkseparation image at 40% and determined my ink crossover points. 
 Then I printed out the 21 step image and predictably the 100% black was low at around 
2.20.  I thought I could boost the photo black in the C position to get close to the 
maximum dmax I had achived earlier at around (2.39); so in the script I changed the 
"Boost K" to "Boost C" thinking that this would boost the PK in the C position.  However 
when I printed the 21 step, I could tell that Eboni was being used in the 100% square.

Therefore, my question is, is there a way to boost the PK in the C position without using 
the Eboni in the K position?  I wasn't planning on using the Eboni with the addition of 
GLOP as I felt that a dmax close to 2.39 would be pretty good, so why complicate things; 
and I have no idea what kind of dmax the Eboni with GLOP would produce.

What I am going to try next, unless anyone has a better suggestion is to increase the ink 
limit on the Cool PK and recalculate the crossover points.  My only fear of doing this is that 
the blacks in the deep dark shadows may block up.

Any suggestions you may have will certainly be appreciated.

Thanks,
Randy