Give it a try and run some tests. I wouldn't worry about grain for contact printing. One of the real attractions of contact printing is that you can forget about grain and think about tonality, micro contrast, and edge sharpness. ABC pyro is a terribly grainy developer, but it's a great choice for Azo and other contact print methods, because it produces a crisp neg with a long scale. ABC would be a lousy choice for smaller negs. I think that the main reason that pyro disappeared as a commercially available option for so many years was from the overall decrease in format size.
As a general rule, I find that my N+1 development time for negs targeted for enlargement is about my N time for negs targeted for Azo, so you might try your N+1 development time for small format negs in Rodinal as your starting point for Tri-X 8x10" for Azo, or if you haven't figured out an N+1 time, just increase your development time by about 20% over normal for Azo and adjust from there.