Installed and working. I designed and printed the case.
Installed and started monitoring via Adafruit IO
I have a few software enhancements in mind. Ability to turn the boost charger on from the web for example.
Also there is a strange phenomenon happening each morning. The voltage goes low enough to trigger the boost charger. I wonder if this is happens when the solar controller first turns on. Maybe I need to set the threshold a bit lower.