Redshift credentials - Secret Manager vs IAM authentication?

The only limitations I'm aware of are the following :

• You'll need to ensure that the driver used by your client does support IAM authentication (please refer to : https://docs.aws.amazon.com/redshift/latest/mgmt/generating-iam-credentials-configure-jdbc-odbc.html)

• If you don't use any kind of Identity federation and need to create IAM users, you'll need to figure out how to securely store IAM credentials (access key and secret key), how to pull them securely from your clients, manage secret rotation.