Digital BW, The Print

I'm still in mental roller coaster to decide on my printer/ink set. 
I'm skipping my original plan to by a R220. Instead I'll outfit my 
2100 with either the UT-7 or UT-3D inks.

I'm working with QTR. UT-7 would my current needs. On the other hand 
the systematic color space approach and the split-tone potential of 
UT-3D appeals to me. 

My questions on the are three-fold:
1) On this form repeatedly the "beta-stage" of the UT-3D inks are 
reported. Is there any view when these inks will have their final 
quality level?
2) I'm not fully sure on the role of the LK ink in the UT-3D set. My 
guess is that you don't need them when using QTR, but you do if you 
print with the Epson driver. Right? That would mean I have the 
option to experiment with sepia on the LK position(as indicated on 
Paul's site) or other toners if I use QTR.
3) On the previous question: I'd like to experiment (presently just 
for fun) with a green toner to get tones at the negative a-axis of 
the Lab space. Can I just mix MIS yellow, (light) cyan and light 
carbon? Or is that put way too simple? I realize the archival 
quality of this toner will not be very good.