Note from author : I had this idea in April 2020 and spent a while trying to come up with a satisfactory (and ideally NYT-legal) grid. Despite the many single-letter answers this is as close as I could get.
by Jacob Wood, Sun Jan 05 2020
Theme Explanation : 47-Down took 2-Down years to produce the answer to 148-Across, 32-Across, and 16-Down. 80-Down could use 8-Down to do it in 113-Down.