Thanks for the advice. XDrip+ doesn't require internet access, and if it did then my GrapheneOS phone has a toggleable network permission for each app that I could utilize if I was worried. I wanted my data stored and backed up on an external database that I then backup nightly as part of my Proxmox homelab. With an external database I can build /use other tools to pull data from the database for that I would not be able to do from a phone app.