Pinion angle question

Yes, I understand the concept. But how much time does the car spend under heavy acceleration compared to part throttle cruising? The shaft in those videos certainly is not under any heavy acceleration. Right now I have a .5* up pinion angle which I don’t like. My plan is to add a 2* shim to lower pinion to 1.5* down compared to trans angle. Will test when weather permits. If the vibration decreases I know I’m on the right track and may try 4* shim to dial it in.