I have been looking at the subject of the mustard and the bees in Bava Batra 18b. My learning partner David Bronson would have spent at least a month on each Tosphot there. But I see there are a few other approaches that make the subject to require at least a year. R. Akiva Eiger, Rav shach and Reb Aaron Kotler each have a whole booklet on the subject because of the difficulty in the subject. See also Rav sharira Gaon. And the RiMigash