This must have changed with 23.04 or something then, because when I set up my home server a little over a year ago, ZFS as root was not only not a part of the install, but also heavily recommended against as something that could be hacked in. Basically you could do it, but you shouldn’t was my impression. I ended up doing EXT4 as root, then mounted my ZFS storage in my home directory.
Enemy and Jellyfin both have Android TV and Roku apps. I don’t have an apple TV, but I imagine apps exist there too.