Not sure I'm following; you want to create a an emphemeral system account and run a root-less Podman container as it? I don't think that's something supported out of the box but you may be able to jury rig something together by putting the quadlets directly in `/etc/containers/systemd/users/` instead of putting them in a home directory (since I'm assuming this is a systemd-sysuser created account and thus without a home).