This is the first I have heard of people 'stuffing' their tarps. I have always folded my tarps, and I have not seen any signs of wear on the folds. I would of thought you would be more inclined to damage a tarp by stuffing it.
I have never 'stuffed' a tent either.
However I do stuff my hammock and sleeping bag.
Guess we all do things differently!
enjoy whatever you do!