Villain is 31/19 reg and my notes on him is that he is kind of stationy. Breakeven over 20k hands (mined).
His wtsd is 27%. He skips cbet and c/r 12% on the flop. AFQ is 42.
He probably tends to not give me that much credit as he 4bet bluffed me EP/BTN, when a fish overcalled my 3bet from the BB. It could've been just an attempt to iso the fish with a WA/WB hand though.

I could've bet bigger, but I also stab here with air a lot, so I like to keep my betsize consistent, also gives him some room to c/r me. When he goes with the c/r, I was really unsure about the optimal line vs this villain.

Would you 3bet flop? And if so, what sizing? What do you think is his c/r range here?

My main problem is that I look very strong here if I 3bet. Even shoving would look weaker probably. Calling seems dirty too assuming he can have a big draw here.