Let's say we open AA72 rainbow and get 3 bet while 250bb deep. We can't 4 bet since if he calls we're seeing a flop with an SPR much higher than 1. We can't fold cause our equity is so good. So we're forced to call and play a big pot deep and we only really like low paired flops or Axx flops (or low trips on the flop but that never happens). Without reads on villain at what point on different board runouts do we need to muck our hand?

For example we call OOP and x/c a 2/3 pot bet on J52r. Turn is an 8 bringing a backdoor flush draw and villain bets 2/3 pot again. From what I understand stacking off requirements are lower in a 3BP but what about in spots like this where we're just trying to see a showdown as cheaply as possible? Are bluff catching requirements lower compared to a single raised pot? Is it exploitable to fold or do we just fold?