The FDIC has taken the position that institutions that have ad hoc programs should not be obtaining opt-ins as there is nothing for the customer to opt into but an overdraft fee. There is no formal overdraft service for the customer to access. The FDIC considers this to be UDAAP since the customer opted into a program that does not exist. Consequently, the A-9 form would not accurately describe your overdraft practices.
The FDIC has not formally published any guidance substantiating its position, but conversations with more than one of my clients indicate that field examiners are continuing to cite this and are requiring look backs and reimbursements.