Ok Bloggs I was guilty of assuming that it would be apparent that capacity was only available after the aircraft was in some semblance of control-I guess I didn't spell it out though. From personal experience with severe CAT the only thing I cared about was regaining control however once regained there is no guarantee it will be maintained e.g. more CAT so thats when the radio call would be appropriate-also as a warning to following traffic i.e. Airmanship. Does that spell it out clearly enough!