Digital BW, The Print

I hope I'm not asking a question already posted.  I'm tempted to try
the MIS/FS inks for my 1200 printer but have a couple questions.

What is the definitive answer regarding how many distinct inks are
used in 6-color Piezography?  I seem to recall past posts saying that
Cone only used the same four inks as used in the quadtone set. 
Supposedly the photo-cyan and photo-magenta positions use the same
cyan and magenta inks and the piezo driver adjusts accordingly. True
or not?

If so, then is their really a need for a hextone FS inkset?  You could
use the quadtone set as long as you know what chambers to put the inks in.

If there are 6 distinct inks in the MIS/FS set how would this
reconcile with the 4 inks used in Piezo (if this were true)? 
Specifically, what would happen if one wanted to use the piezo driver.

Anything that would clear this up is appreciated.

Mike