Well understood. Starting to use Hubitat has made me actually utilize a couple of RPi3 that were just sitting in a storage box along with some Western Digital Pi Drives I had bought, tested, and then really didn't have a need for later.
If you wish to startup without choosing a database, I did a similar project collecting data to a simple CSV file. It allows me to look at the data in Excel and see what my next step might be. Somethings I'm simply looking for an issue and don't need to plot.