I heard sauce talk about big 3bets in some of his videos, he uses big 3bet sizes aswell. I believe the main idea of it is to decrease the edge of being in position and making 4bet/folding hard (you either have to 4bet shove which risks a lot of money or you have to 4bet really small and thus you give your opponent good odds to call 4bets).

I don't think there's anything particularly special about playing againts these big 3bets vs. playing againts smaller 3bets. Perhaps you want to 4bet slightly more linear range because you're forced to 4bet with a smaller size? And hands that you want to cut from your range are probably mainly offsuit hands (a hand like QJo BTN vs BB for example).