Ha! yes. The buildFHSEnv function works by creating a separate namespace akin to Docker containers but without complete separation from the host system (I hint to this in my post). It then hosts the libraries in /nix/store into this namespace.
Not related to containers but I've had quite a lot of success using NixOS as the host OS. Setting up services like jellyfin is as simple as adding services.jellyfin.enable = true; to the config file.
This is the way. +1