Micro 6max Rush is a little tighter preflop than ring games imo. I think it's because people know they can immediately start playing a new hand if they fold, and also because it's not the same two people in the blinds watching you steal every time. So stealing at Rush is very profitable, the tags almost always just fold, and the fish will call and c/f the flop alot of the time.

Micro 6max tags tend to be pretty nitty, 16/12 would be typical, probably they're so tight because they're not comfortable postflop. Light 3-betting hasn't arrived at 5NL yet but at 10NL alot of the 'tags' will have 3-bet %'s around 8-10, yet another indication they're more comfortable with preflop, esp since alot of fish just aren't folding pre.

Raising A9 here and 3barrel b/f'ing smallish with TP is going to be +EV in a vacuum, I'd say. But raising, folding, or calling pre are probably about the same. FWIW villain here had A4o. Regardless, I like a river b/f better than a c/c against this passive player because I have no evidence he'd ever bluff big with a busted draw but he does play all his monsters this way. Obv he could call down with worse. And with the A pairing otr, you could reasonably expect a call from any K too.