> If i'm reading this correctly, can run Immich from a Raspberry Pi 4? That's pretty cool.

Yes! It runs completely fine on a Pi, except for the machine learning service. The good news is that you can run that service on a separate computer with a GPU and point Immich to it. Immich will use it when it's available and I think you can configure it to run all the queued ML jobs at a certain time when you expect the computer running the ML service to be on.