Everything about this hand is really bizarre. A little more context (in the form of reads and stats, and info about the stakes) might be helpful, although the preflop action alone makes the BTN seem like a very weak-passive. Not sure if you had a read on the BB or just figured that people go apeshit from the blinds in spots like these.

Your iso sizing seems a little small to me – imagine how this hand plays out if the BB had folded and the BTN flatted. Then there's the other universe where the BB ships over your four bet. Are you calling?

As played, the BTN's line makes me think his range consists of hands that he really wants to see a flop with and then hit it and win (small/medium pairs, suited connectors). This is the perfect flop against that range because it's both light and dry. I'd expect him to fold close to all of his air to almost any sizing; so the question is whether shoving will get him to fold hands you are behind and that a 1/3 PSB won't – 87s, 76s, 88-TT (I'd expect a normal c-bet to fold out 22-33 and 55-66), or a very passively played AK. There's also the secondary question of whether you might get called by worse – a stubborn ATs or other suited Ax, 86s, 65s (which you're barely ahead of). Balance these considerations against how shitty your equity is vs a made hand that will call you no matter what (you have ~17% against Qx hands, 4% against sets) and I'd lean towards a smaller c-bet, especially since Mr. Passive Pants isn't going to ship over you light.