Currently, the config app only provides the generated config for download (and maybe there's some k8s magic?). For easier use as a single container, the config app should write the config file to the correct path so that running with a volume mounted "just works". For example, this should work:

podman volume create quay-config
podman run --rm --publish 8443 --volume quay-config:/config/stack quay.io/projectquay/quay:lando config
^C
podman run --rm --publish 8080 --volume quay-config:/config/stack quay.io/projectquay/quay:lando