Possible/rational to create custom color with ConeColor + custom profile?

Is it possible to create a custom color inkset for an Epson printer that is not the same as the OEMs?

I like the red/orange inks in the P600, but it only has a cyan to make blues. Also, I have a Piezo-Carbon system, so I do not need the four grays on the P800 or other larger printers. Could I build a set with red/orange/blue (or maybe a violet or green!) replacing the three grays in a P800? And could a usable custom profile be made so you could get predictable results with the Frankenstein’s Inkset?

Or is this just cray-cray to consider?

I usually print artwork, not photos, and on Han. PhotoRag 308.

sure, but you need to do this with Gutenprint and learn the their API.

It can all be done with an XML spec and a custom build of Gutenprint.

best
-Walker

Have you done a custom color set for yourself or a customer?

A custom build sounds … complicated.
Would such a color set involve a profile being made, or is everything somehow in the Gutenprint build?

Would you recommend a primary blue, or violet or green to add to R/O and LtM/M LtC/C and Y and Black? Maybe the Orange isn’t as useful as a green in the mix.

EDIT:
Looking at the IJM sales site by printer, you HAVE refillable carts for P400/600/800
But NO refill carts for P700/900

Is that still the case?