There are cases where the current ThreadSafeInterfacePtr is not ideal.
Typically, an object A needs a thread safe InterfacePtr to an interface that should to be allocated on a different thread in a method of an object B.
With the current design that means B needs to push the thread safe InterfacePtr to A once it's being instanciated, so B needs to know about A.
Ideally ThreadSafeInterfacePtr would be split in 2 so A can keep one end of the thread safe interface ptr and B gets the other part and initializes it from the other thread.