I’ve looked briefly into seafile; I’m fine, happy really, with the synology for file hosting, it’s just the caldav, the photo management (I have immich but there’s no easy way to move albums from syno to imm), stuff like that. And the fact that it all works together (reverse proxy, apps, web UI…) makes it illogical to move away for anything else than ‘principle’ or ‘insufficient hardware’.
I have truenas running on a proxmox system but it appears it wants more than one drive? But I don’t have matching drives for raid at the moment. That was/is something I’m looking into longer term, once I decouple the data from the services.