based on the video, I must admit I misunderstood your description. I was expecting more of a hesitation when you "blip" the throttle. But in your video, I don't see or hear any hesitation, which is usually what I (personally) would associate with the description of "cough" or "stutter". Maybe someone else can better identify/detect what the OP is describing?
OP, I'm certainly not disputing your situation, I just wanted to admit that I lack the diagnostic intuition to be of any real help in this case. I look forward to what others have to say.
70 to engine rebuild faster than you can say "poofff!"