I'm not sure tbh
I need to read up on how to react to 3bets for def, here though, and this is just off the top of my head, if we 4bet and he comes over the top we're almost always behind barring some spazzy shoves with med pairs <TT, but he has pos so if we 4bet and he just flats then are we not in the same position as if we just flat his 3bet, except with a bigger pot?
If we just flat his 3bet then we end up with an SPR in the 3/4 region which i think makes our TT v.easy to play if we have an overpair or the boards dry with 1 broadway, stacking every time, its only when an A/K comes down, or a board with 2 broadways on it that we have a diff decision.
If we 4bet do we not fold out a lot of hands which we have good equity vs, Axs PP 77-99 Sc's and just get called/shoved on by everything that crushes us?