QTR-Quadtone RIP

I am using QTR with Jon Cone's K7 inks and have finished the process 
including making the icc profile with Roy's cool Create ICC program.  
When using the profile, the print is a close match to my calibrated 
Sony Atrisan, but the print is a bit more contrasty than the soft proof 
(Windows XP)and the deep shadow areas of the soft proof could be a bit 
lighter.  

Is there a way to tweak the icc profile directly to clean this up or 
should I use another approach?

Thanks,

Bob