Check out the "Keeping Pace" newsletters from 1994-1996. I had first shown Bob some dye transfer prints made by Girard Aniere in 1994 using UltraStable films (the same ones you have) to form the matrices. Although the enlarged separations were made with a 400lpi screen, the print appears to be continuous tone (even when viewed with a high power magnifier) because of the diffusion of the dyes. I've uncovered some correspondence with Bob in 1996 also discussing this approach to making dye-transfer prints but I can't refer you to any specific issue of his newsletter that covers this topic.
BTW : Bob Pace, in 1997, published his book Making Enlarged Separation Negatives for the UltraStable Process, which may be of interest to those who wish to use con-tone negatives to produce color carbon prints.