In my Kodak catalog black & white duplicating sheet film ( 4168 ) is a direct positve product that produces duplicate negatives when contact printed from your existing negative. I think you are correct to assume that the image will be very fine grain and have lower contrast than a camera film. Film speed is not specified.
I used some Ektachrome duplicating film years ago in a 35mm camera and the result was a very soft color rendition. That product was ASA 16 for tungsten.
P.S. There is a big difference in COPY film and DUPLICATING film. Copy film produces a negative. Duplicating film duplicates the original.