DDSPSMC11_ — API needs a standardized way of downcasting API entities

Right now, API entities are wrapper templates around the actual Delegate implementation, as in (depicted a bit simplified):

typedef TEntity<EntityDelegate> Entity;
typedef TPublisher<PublisherDelegate> Publisher;

If I have an entity of type Entity, and I want to widen it to a type Publisher, I cannot use a regular cast because I need to cast both the wrapper and its Delegate.