The response narrows to a fortress: 4-bet kings-plus, call with nut potential, and refuse to bloat the pot with anything else.
4-betting narrows to the very top; suited hands with nut potential call more. The question on every street becomes: which hands are happy getting 500bb in?
You opened middle, the cutoff 3-bet with position. Their range is wider than a blind's — your response widens to match.
Assumes a standard 3-bet; 4-bet to ~2.2–2.5x the 3-bet. Deep, favor calls over 4-bets — a 4-bet pot at 500bb+ commits you with range disadvantage.