Scenario: BTN opens 2.5x with ~50% and SB 3bets ~15% to 9bb, 100bb effective. Flop Ah8c2d, SB cbets slightly more than 1/2 pot. Turn Qs, SB bets again slightly more than 1/2 pot again. I assumed that as BTN I shouldn't have a raising range on the flop. Should I now have a raising range on that turn? I have difficulty to understand which strategy is better. We assume SB is a good player and pretty balanced in this spot.

Thanks