Mega-deep, initiative is overrated and position is not. Call, see a flop, and outplay them for four streets.
3-betting is nearly reserved for the top of the deck. Position and nut potential dictate everything else; offsuit broadways are mostly gone.
A middle open, you in the cutoff. The opener is wider than EP, so 3-bets earn more — but position still says flat the speculative hands.
Assumes a ~4bb open; 3-bet to ~3x the open in position, ~4x from the blinds — larger as stacks deepen.