CO is 45/40 over 21 hands, small sample.
SB is 23/18 with a 3-bet of 7.3%, squeeze of 7%, 3-bet in SB of 8.8%

Maybe I should have 3-bet CO myself to isolate? As played I decided to call since I'm OTB with a good multi-way hand.

I would expect SB to c-bet a lot of his strong hands on this flop due to the straight and flush draws out there, and to trap a bet from CO.

When both players check, I'm not sure if checking back or betting is best. If I check back and turn an Ace, it might not be good for me since SB could easily have AJ/AQ. Turning equity might be nice, but why wait for that when I can bet and get folds now?

I decide to bet and SB check/calls. I think he might be check/calling 99-QQ here quite easily, or maybe a very weak Kx that he was 3-betting light with.

Given the sheer # of draws on board I would expect villain to be leading with his strong hands like sets, since I am checking back quite frequently here. So I believe when he check/calls flop and checks this turn, his range is quite capped and I might be able to move him off his hand with a slight overbet jam of $155 into a $113 pot.

Should I bet or take the free card? I definitely have strong value hands in my range like 55, 66, 65s, KQo/KQs, and also a lot of high equity draws such as JTcc, ATcc, ATdd, 87dd, T9dd, etc.