Last time I tried, there was no prebuilt client for Jellyfin on my Samsung TV. I had to put the TV in dev mode, cross compile and install their experimental code, and it honestly wasn’t that good a client.

I don’t use the paid features of Plex so I’m just holding my nose and keeping it until the alternatives become viable.

Docker Desktop isn’t needed on Linux. If you want a UI, try Portainer

All I know about ZFS is that there are weird patent or closed source encumbrances or something. I hear it’s good, and it seems popular, I just avoid proprietary Oracle products.

As for btrfs, the only thing that’s claimed to be unstable is raid 5 or 6. And people use it in production saying the claims are overblown. I don’t. I use it in raid1 mode. But raid1 in btrfs doesn’t require a bunch of matching drives. It lets you glom together a number of mismatched disks and just puts every block on more than one of them. So it’s a nice cross between a raid and LFS or JBOD.

Just btrfs.