if I’m understanding you, you’d like to use any one channel at 100% direct on to the substrate?
... not exactly, and i certainly do not imagine ever wanting or needing to use 100% of any colour.
What i want to do is... effectively treat the 9900 as a simple 6 colour device (CMYKOG). (Much like a litho press i guess... but vastly more stable).
Firstly I want to be able to set ink limits for each of the six channels for what i judge to be the optimal balance of Hue, saturation and Brightness.
My reason for wanting to do this is that, from what i have seen with other epson printers, the ink limits are often set lower than i would choose to use them (which i assume is probably because profile makers have to cater for drying times across a multitude of atmospheric environments?). Whenever ink limits are lower than they could be... they restrict saturation around each of the colour channels.
Secondly i want to linearise those six channels.
Thirdly, the fun bit, i want to make and send six colour separations through the printer.
I am not 100% sure that it will definitely be better than the results achieved via epsons profiles... but i'd hope so.
Admittedly this relies on someone making 6 colour separations that take into account grey balance, and maximum ink weights where there are a combination of inks... but it can yield very good results, and is common practice in repro-houses that engage in HiFi work (hexachrome etc).
To date i have only ever been able to do this myself with CMYK via 4800 / 9800, and one of the attractions of the 9900 was the O&G... but for some reason colourburst are not providing the same level of user control to the 9900, as they did / do for the other epson printers. (No idea why... but it is a shame as the rip is very good for contract proofing etc).
I still have and use colourburst for contract proofing. The silly thing is i feel that my objective is so simple that it shouldn't really need yet another expensive rip. It is probably how all drivers worked in the beginning... but as technology and colour management got clever... some simple things were lost along the way.
I know this is not a way many would want to work, and it is only any good for someone working in a closed-colour-loop, which for my prints, i am.
Having set out to clarify my purpose... I am not sure if i have done that or not?