I'm not sure how the precedence will work if auth_config and env_config is defined in each role (pretty sure it's undefined if the same var is defined in two roles/<name>/vars/main.yml files).

The way I was thinking we would do this is defining these two vars one time (right now they are defined in the lms role but maybe we should move them) and then override keys in the cms, lms, and lms-preview roles.