I prefer 3bet preflop with so strong hand Vs min raise and 54/27.

X/r reraise is nuts. I don't like his agresion.

If villain fish there is 32 combos of straights. And 9 combos of 88/66/98o and 9 combos of 86o. I don't think villain have any draws according to his agresion.
Also in game I prefer check his cbet, Wsf, w$sd. If cbet is high (more often cbet 2pairs and sets) and high w$sd, I think we can call it by pot ods.

I don't know, at a certain point even a fish/whale's range becomes quite isolated.

Part of me likes flatting the 3b to keep his range wide and allow for further mistakes on later streets.

We can certainly construct a range where we're doing quite well getting it in flop, but I just think even fish think twice about sticking 160 bb in here with AA.

I agree with 3betting pre 150bb deep vs a whale IP. makes it easier to GII on these flops as well. As played I don't think I'm getting it in OTF, all tough I'm raising but I prefer him to bet or us when he checks.

What is your reason for not 3betting preflop? Personally, I don't see why you flat there.
I like your 3b on flop, yet would flat his 4b. That said, I don't think it matters too much. Don't think he folds that often after X/r+4b on flop, so if you think you are ahead (which is debatable but reasonable versus a whale) you might as well push flop. Simultaneously, I don't think you lose that much value if you flat and scary cards arrive. He is a whale, so much money is already invested and SPR is so small. Which is why i don't think theres a big discrepancy between your strategie options after your 3b on the flop.

Yet preflop you most likely lose a lot of value by flatting, so I would be more concerned about your decision there.