It seems to me like we just have to flat a 4B with quite a few hands in the SB when 4B by BU. If we don't we either can't 3B very much, have to 5B a lot, or fold way too much to 4Bets.

But it also seems like it is very hard to play a hand like 76s OOP after calling a 4B by BU. Would we prefer hands like KQo for their high card value and the potential to make big pairs?

Or do we just not care enough about defending enough at stakes like 100NL and 200NL?