The function setup_config tries to find the current configuration file inside an environment variable BB_CONFIG_FILE, which is benchbuild specific. This will provide an awkward experience in custom user code.
The function update_env relies on the existence of various configuration settings at specific nodes levels. This will most certainly break user code.
Possible solution: Move this code to benchbuild.settings, as this is specific to benchbuild. User-Code should get a more generic version of initialization.