Did they ever make it so you could add photos to your library by means other than the Immich UI?
Most of my photos just get copied to a folder on my NAS in Windows. The main reason I went with Photoprism was that Immich didn't support that behavior.
External libraries do this, but fwiw when I tested Immich I ended up with a ton of missing thumbnails in my external library and there seemed to be no way to detect and repair them. That was a deal breaker for me and I went back to Photoprism. Immich looks really great though other than that.
Set Immich up a couple weeks ago and I'm surprised how good it is. Their docs included a simple cli tool to bulk import all my Google photos. Mobile app is working great. I'm really impressed with the search too.