Advise for influxDB and zram on OH3/openhabian

This is what I recommend you trying to achieve.

Run openhabian on sd card inserted in the PI.

Put another sd card in card reader into PI to mirror for failure.

Mount the SSD and get stuff that writes alot to move to SSD.

Do automated backup to SSD as well.

You probably already have all the hardware needed to achieve this or its cheap to do. This way if you have a failure you have multiple ways to recover.