I don't see a reason to use black inkjet. It's overkill for the purpose. A roller or spray nozzle setup would be less complex, cheaper, faster, and more reliable.
Maybe inkjet for numbering, etc., but I think a roller would be simpler and faster.
An existing inkjet printer line is less expensive, with the majority of tooling up, already amortized, and modifications to inks and ink delivery being the key modification needed, IMO.
Is there no already"ink jets" already spraying "skin tissue" for medical uses?
Taking it a step further, liquid emulsions could likewise to paper, polymers, etc, by using a standard compounded fluid(s).
It may be that someone here or someone they know could experiment using traditional Indian Inks of a density that an blackout ink or an emulsion would require plus 10% > greater density than required.
I believe the technology is in place and beside the modifications of existing machines, inks, etc, the next step would be to workout the settings and work load requirements.
Imagine using thin Yupo paper in an emulsion "ink" for making 'paper' negatives for medium and large format cameras, or applying platinum-palladium, or other emulsion/sensitizers to a quality Alpha Rag sheet or board, which you could print museum grade prints with!
Would Ilford etc al, be interested in that sort of market?
We need to try, those that can, until we have success, so our future is ensured for the time when such things might be the only material available to continue Analog Photography with, whether company compounded inks are made in small batches or we are able to compound our own emulations in our own spaces.
Think about it.