In competition the singlet is usually a required attire. You can't show up in cut-offs and a T-shirt; i tried once. The belt I don't see helping with the lift at all. For me it just causes cramps. I used to try wearing a belt to hold my umbillicle hernia in but it never worked.
All that said, it is impressive for sure. But the 2nd lift at 716 I think would not have counted in any meet I've been in and the "record" (I'm not hating by any means) is very questionable. Every meet I've competed in they tell you when to lift. You lower the bar then a judge will holler lift. Even in training I always count to three before the concentric part of the movement.
Still an awesome lift! And I'm still trying for 600lbs. Of course I'm pushing daisies (60 )in a couple of years.