QTR-Quadtone RIP

Hi there,
Apologies if I'm asking a dumb question but I've removed all colour inks from my R2880 (as they kept clogging up) and now have only the three Black/Grey inks left in the printer. These are supplied via three (out of eight) ink tanks at the side of the printer in a CIS system provided by Marrutt UK (Lyson distributor).

This works fine, but I have had call recently to look at reinstating the gloss black ink, so I can use Ilford Gold Mono Silk paper.

So I'm thinking that I should be able to use one of my empty cartridge slots to accommodate the fourth (gloss) black ink.

I did look at the Piezographic ink set, but I'm not looking for higher quality mono images and spending silly amounts of cash, just for a way to accommodate both gloss and matt blacks on the same printer at the same time.

Would QTR help me achieve this? If so, where would I start?

Kind regards
Guy