Alright, so, I got myself in gear a little bit at least enough to start to harvest. One plant was chopped on day 71 (4.21.20) and the main colas from four more plants got chopped and hung to dry on day 73 (4.23.20). For the most part, the plants just got water from here on. There were two smaller, green as hell plants that got nutrients another time or two, but otherwise water for the remainder.
I was looking with a 30x magnification jeweler's loupe so I think I took the plants about when they were ready. Maybe a bit early on the first plant, but not by much. Gauging and finishing the harvest got much more difficult hereafter.