Docs: "environment variables" not clear

The configuration overview says

Gunicorn first reads environment variables for some configuration settings.

but if I actually look at the list of settings, it seems that this list is very limited.

Is this reading correct? If so, my documentation issue would be "this can be clarified". As it stands, to me the wording is somewhat suggestive that you might configured more via the environment (other than via GUNICORN_CMD_ARGS) but this is simply not so?