ManagedIdentityCredential ignores identity_config in a token exchange environment. Token exchange only accepts "client_id" so doing anything with identity_config requires first deciding what to do with values other than {"client_id": "..."}, and a redundant client_id kwarg. My first thought:

• identity_config + client_id = ValueError
• identity_config != {"client_id": "..."}: ValueError
• otherwise, client_id=identity_config["client_id"]