Just a short update today.
I got the last of circulation fan and its wiring done, but ran out of time before I could install the fan controller. So I temporarily wired it up sitting out on the counter top, closed everything up, and applied power. It all seemed to be working fine, but the real test will be tomorrow, when I see if it can get the cooler side down to 35 while still keeping the freezer frozen. Stay tuned!