I’m speaking from experience. My wife’s car is 3” down in the front and a bit over 2” down in the rear. It has stock control arms and factory drive shaft.
It doesn’t bind anywhere, Doesn’t vibrate at any speed.
I’m not saying it’s pinion angle is optimal, but this is a street car and is not raced. For that purpose, it’s fine.
As I mentioned, if the intention is to ever race the vehicle, adjustable arms to correct pinion angle would be warranted.
For a street cruiser, this isn’t really any different than putting a couple full sized adults in the back.