Yes that is correct then. So Cloudron would not touch the env variables for OpenID which you have set.
One maybe easy to forget step ist, you have to restart the app in order for it to pick up the new environment.
Otherwise can't see why setting the same values like Cloudron does would cause it to not even know about that auth strategy.
Just for reference this is how the Cloudron startup script would put them (if cloudron usermanagement would be enbled): https://git.cloudron.io/packages/librechat-app/-/blob/main/start.sh?ref_type=heads#L92
