Mixing RAM is OK. I’ve been running consumer PCs with mixed memory for years.

Better not put different sticks on the same channel, though. Depending on your MB you may need to set frequency manually to 1333, but most likely it will work without that.

Not my solution, but I liked an idea and thinking to use it too - copy backups on external HDD and put it into your car trunk. Maybe have two drives in rotation.

It eliminates a need to drive somewhere for rotation, and any cost of renting a safebox.

Doesn’t protect from a serious disaster like forest fire or earthquake or nuclear war, but I keep the most important data in cloud, and if my house and car burns I would be having other problems than worrying about some homelab snapshots.

It looks so cute! Too bad Kobol has shut down - I’d buy a NAS from them