Digital BW, The Print

One other thought that won't really help the hextone effort, but, is 
there any reason NOT to do actual quadtone curves with the quad inks?   
If each of the 4 positions in the quad were occupied by a discrete ink 
color is there any reason to believe that PhotoShop would then use those 
ink values to properly repro an image with an applied quadtone curve...?

Admittedly, this is beyond my own base of knowledge...

However, if duotones and quadtones have served pre-press for eons.. why 
not use that for the quadtone inksets and simply profile media to match...?

If it worked, some compromise of the method might be feasible with the 
hextones..

Keith