Given the large number of heavies handled at JFK and if this request is physically impossible to achieve then, I’m guessing that this specific request is not a common one from ATC, otherwise they would well know that it’s unachievable and probably wouldn’t bother asking in the first place.
I’ve heard war and peace from other BA aircraft when asked to do something they can’t in other parts of the world, when a simple ‘unable’ would have sufficed. They did themselves no favours here with the lecture.