Zammad log levels

I have installed zammad via docker-compose. Its log output is insanely verbose, as the log level is set to info. When I submitted a feature request for zammad docker compose to reduce its verbosity, I was told that Zammad only supports the two log levels “debug” and “info”. Is this correct? Would it be possible to add a log level “warn” and set the log level in production.rb to it?