It was common practice in the early 20th century for users to sensitize plates after they were purchased. "Photographic Facts and Formulas" by E.J. Wall, 1924, has instructions for this. He has a recipe for Erythrosin, and recommends using the plates within a few days after treating them. If you don't already have the book, it can be downloaded as a .pdf from the internet.
Don't know if you're interested in dunking the finished plates in a dye bath, but just thought I'd mention it as an option.