I might have misled you about the complexity of my setup, sorry.
I didn't even setup something like FreeNAS or something. I just setup ZFS and enabled SMB and NFS on top of it. This is on a spare computer that I've setup with Linux.
Then I've setup `cron` tasks that run various scripts that just download various YouTube playlists -- hand-picked and curated by me.
Nothing you'd call an intelligent software. Just hand-picked places on YouTube to monitor and sync once a day.
It's only automatic insofar as `cron` executes `yt-dlp` with a bunch of URLs.