How do I turn off Trusted Advisor's "amazon rds reserved instance optimization" (check 1qazXsw23e) while keeping all other TA functions in place?

You can exclude a resource from being checked. But it's on the resource level, not check level.

To turn off the "Amazon RDS reserved instance optimization" check while keeping other Trusted Advisor functions, you can exclude that specific check ID from the results.

The check ID for the "Amazon RDS reserved instance optimization" is 1qazXsw23e. You can exclude this check by clicking on "Suppress" from the Trusted Advisor dashboard or API.

When you suppress a check, Trusted Advisor will ignore that particular check for the current AWS account and region without disabling the overall Trusted Advisor service. This allows you to selectively turn off certain checks as needed while keeping other checks enabled.

The suppression will remain active until you specifically click on "Unsuppress" to re-enable that check. You can also suppress checks through the AWS Support API by calling the suppress-check-results operation and specifying the check ID to suppress.

This allows you to selectively control the visibility of certain Trusted Advisor checks and findings without having to disable the whole Trusted Advisor service.