I don’t understand why you even change the names and ports. If you have a seperate docker-compose.yml file for Immich, the names won’t clash with other services (except if container_name is duplicated, but services like portgres and redis normally get one assigned automatically).

The ports are also limited to the container networks, so running several postgres instances still allows all of them to use the default port (except you pass them through from the host, which you normally shouldn’t do in closed networks like Immich’s or you run all services in network_mode: host, which is often a bad idea).