QTR-Quadtone RIP

I've created my curves and have linearized them.  Comparing the densitometer readings to 
the ideal density readings aren't too bad for the most part; although I would like to tweak 
them just a bit more.  My highlights are consistantly a little too dark as are the shadows; I'd 
like to get a little more separation in the shadows.

Can you use the "GRAY_HIGHLIGHT=" and the "GRAY_SHADOW=" entry to adjust these areas 
and get more separation after Linearization?  I haven't had time yet to experiment with these 
controls; but from the documentation I've read I thought these controls were for those that 
choose not to linearize.  I don't want to lose any of my dmax, but just get a little more 
separation leading up to the dmax. 

I'm not looking for perfection, just a little more control.

Any advice or reference to other documentation is greatly appreciated.

Randy