UTG is a maniac rec raising around 45% from every position. BTN is an aggressive reg. Here I'm widening my 3bet range, i'm sizing down a bit because i don't want to put too much money with 3 players behind with such a wide range. I can't tell if BTN knows i'm adjusting to the maniac, but if he does he may be widening his cold-4bet range too. After the maniac coldcalled I think there is enough dead money in the pot to justify a push with A9s, with the 9 unblocking some weaker cold4bets.

What do you think? Is it reasonable to assume reg is adjusting?