Some further reading introduced me to the intriguing, though short-lived, Kodak Ektaflex process of the early 80's. Between the developer, which I understand was problematic, and the Polaroid patent suit, it sounds like it was doomed from inception.
What else is/was there?
The same time Agfa had a range of dye-diffusion materials for rapid access too. With seperate receiving layers for professionals and as integral system (in contrast to Ektaflax) for amateurs.