In this session, I finished riveting to the left spar all of the nutplates that had in stock. There are still several dozen places for nutplates that I cannot populate yet, so I will have to come back to those later.
However, I continued making progress countersinking the remaining holes (and researching about the proper depths). These holes need to be countersunk to allow a dimpled wing skin to sit flush in them, so the consensus from the Vans forums is to countersink them to be slightly deeper (0.007" precisely) than what a flush -3 rivet would take.
What's next? Continue on with this countersinking... There are a lot of these holes!