Digital BW, The Print

After reading many posts on the subject, I recently
bought a 1280 printer for my bw work.

First I tried the VM inks. Netural and cool tones
seem to work reasonably well after futzing with the
curves a bit. But the warm tone curves seem to suffer
somewhat from crossover effects in the shadows, as
the blue mixes in prior to the black taking over.

Then I tried the FS inks. Turns out that this inkset
only uses four shades (not six). And I'm seeing a
light band just before the black ink kicks in. (I'm
assuming this comes about because the epson driver
is blending as if C and M are darker than PC and PM.)

So how best to print warm tones on the 1280? Invest
in the piezo system, or can anyone share an alternate
1280 CIS workflow?

 -Mark