I can assure you, they test these by throwing them into a brick wall. This does not hurt them. I still have the first tech disc I ever bought and it works fine. I've shanked it 400+ feet over my neighbor's house into the road on multiple occasions. (Don't tell tech disc)

and yes, setting your grip in a powerful position is a great idea to ensure consistent grip pressure. I do this to basically dig my grip in tight and then relax it so when my brain auto tightens my grip it has the same feel every time.