Currently for a BlackBoardInterfaceListener and BlackBoardInterfaceObserver you have to add all interfaces and interface types before actually registering the listener or observer. You cannot add an interface later. This has nasty effects like having to create proxies if you want to listen for interfaces that you created during the usual thread lifetime (for example opening all new object position interfaces like in the world model).

The listener and observer base classes have to be extended to allow for setting a BlackBoard instance that can then be used to communicate later additions and removals.