Button is likely opening super wide so I like a 3-bet as you're likely ahead of his range, although not by much. Calling is fine also. If 3-bet, I like going $3+, maybe $3.25 (as you already mentioned, you updated your 3-bet sizing). Now, personally, I like the same sizing whether in position or not. Yes, you're right, you want to get more folds when you're OOP but at the same time, you don't want to bloat the pot OOP. So opposing forces. Same for IP, you want to 3-bet smaller because you want more calls but also, you want to play bigger pots IP. Around 4x sounds about right regardless of position. But that's just me.
Flop is good for Hero. There's certainly much worse flops at least. I bet $1.80.
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