QTR-Quadtone RIP

I've been trying to create curves for my r2400 using the following 
ink/paper setup:
Hahnemuhle Fine Art Pearl
Epson UCpk, MIS EZW Yellow, LK, & LLK.

Now I know that the LK & LLK are a little different than the UC inks, 
a bit warmer I would think.

I began by using the QUAD R2400 Ilford curves as a jumping off point.

Creating the neutral/cool curve seemed to be pretty easy, as it was 
not using the yellow ink at all.

On the other hand creating the warm curve plum eluded me.  I finally 
designated the yellow ink to "copy from curve" K with a limit of 60.  
Now this did create a pleasing curve and I was able to create an 
almost perfectly diagonal linearization.  The problem is that when I 
printed out a gradient test file that included concentric circles to 
help evaluate how smooth the linearization really was, I realized it 
was close, but no cigar.

I then compared a gradient test pint of this ink set using the Epson 
ABW  b&w driver.  It was absolutely smoother.  I can imagine a 
smoother gradient but not by much.

In lies my conundrum.  If I use QTR I can get the warmth I want, but 
can't seem to achieve a smooth gradation.   If I use ABW  I get a 
smooth gradation but can't get a very warm tone even when I place the 
settings at 5h, 72v.  Can't go much higher than 72 and I'm not even 
getting close to the warmth I know the ink can achieve.  Having 
printed a purge strip of the "yellow" MIS carbon ink I know it can 
get much warmer.

Am I missing something really basic here?  Any help in figuring out 
how to refine the QTR curves or to cause ABW to use more yellow ink 
would be greatly appreciated.

Kevin