I am using ModeShape 4.0 and try to set a named policy. ModeShape throws a javax.jcr.security.AccessControlException: Invalid policy class (expected JcrAccessControlList). Does ModeShape support named access control policies at all?
No, it doesn't. It only supports the semantics of AccessControlList. Moreover, it only supports an access control implementation obtained via the access control manager's getApplicablePolicies or getPolicies. In other words, it doesn't support a custom AccessControlList implementation.