Earlier today I downloaded Quadtone RIP and had a bit of a play, using it in place of the Epson R2400 driver. It's a bit basic and stripped down, and requires considerable application of the force in setting up, but I managed to put together a profile by eye and by guesswork which used photo black, light black and light light black together in a tritone-like configuration. The results looked slightly warm, as though they were lightly toned silver prints, but even at my very first attempt I managed to get a far nicer tonal scale than the Epson driver.
I've attached a (very low res) version of my test image. I printed on Epson Premium Glossy and on a Kodak glossy paper (I forget the name -- I don't have it to hand where I'm typing this). With the Epson driver, in retrospect all of the prints look like they have a bit too much ink piled up on them -- this was particularly noticeable with the Kodak paper. The Epson version obviously used quite a bit of light magenta and light cyan to tone the image more neutrally (as evidenced by just how fast the printer gets through those inks! Ouch!). I was quite careful in setting up the profile to limit the maximum amounts of ink used by each of the three basic colours, and I think this must have helped, because in the Quadtone RIP prints there is no sign of excess ink pile up in the shadow areas -- my first attempt print had a nicely long tonal scale, excellent detail and quite a glowing/luminous look to it.
The Epson results were good, but this is better. I think this software will probably find its way into my workflow, but I'm obviously going to need more fiddling and tweaking to get things exactly right.
Do other people here use Quadtone? What kind of configuration are you using? Are you correcting for the warm tone, or going with it?
For reference, the image was shot in Yosemite valley (the mountain in the background is El Capitain) with a Cambo Legend 4x5, 150mm Nikkor W at about f22 (which was a mistake, because I lost a bit of sharpness as a consequence I think), Better Light Super 6K scanning back at 8000x6000.