The Set-PASDirectoryMapping AuthorizedInterfaces ValidateSet is missing "IBVSDK":
https://github.com/pspete/psPAS/blob/master/psPAS/Functions/LDAPDirectories/Set-PASDirectoryMapping.ps1#L78
Can it be added?
It's also worth noting that the Directory Mapping REST API's "AuthorizedInterfaces" is actually the interfaces that are NOT authorized. CyberArk has acknowledged this is the opposite of the intended behavior and they have an open bug. Here's the related case:
https://community.cyberark.com/s/case/500Vy000013YZvc/rest-api-directory-mapping-authorizedinterfaces-parameter-broken