4bet pot on the turn

I don't think this is a good hand to 4! with. Stronger hands or bluffs. In general, I would go bigger with 4!s OOP, particularly at these stakes.

On flop I would bet 12.5 BB at most and on turn I would bet again to charge KdQd, AdQd, and Ad, Kd

I would check any river except the jack

Turn: (92.7 BB, 2 players) Q♥
Hero bets 20 BB, BTN raises to 173.7 BB, Hero ?

Don't understand this. Turn seems like a check to me

Since with the Q turn we are behind two out of the three hands you list I do not see how we are "charging" them.

I like the 4-bet pre, CO vs BTN this seems close to mandatory 4-bet until you have enough stats on villain to deviate.

would bet much smaller on flop as bassel suggested ,anything up to 1/3 pot is probably ok.

As played I would check the turn, no value to be had unless you go something ridiculously small that would just be raised by villain anyway

Just jam turn.

Bet smaller flop , and obv jam turn.

I would just fold. It smells fishy but it doesn't seem like there are many flush draws out there in a 4-bet pot. And you have the J♦ which makes bluff catching even worse. So you're hoping he has like TT/AK making a superhero play, reading into your small bet-sizing. I guess it's a slow-played AA/KK or the occasional QQ/AQ.

Also curious why people say jam turn? Makes no sense to me. I could get behind a call with reads but I doubt it's winning vs most.

I guess because SPR is low you should in theory shove wider, but to me I prefer to check.

Thanks for the answers everyone.

The solver indeed jams turn as suggested by Hz93, balancing with AK to make opponent's pocket pairs indifferent.

€0.10 NL FAST (6 max)

BTN: 293.7 BB
SB: 109.2 BB
BB: 101 BB
UTG: 164 BB
MP: 122 BB
Hero (CO): 112.7 BB

SB posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has J♣ J♦

fold, fold, Hero raises to 2.5 BB, BTN raises to 9 BB, fold, fold, Hero raises to 23 BB, BTN calls 14 BB

Flop: (47.5 BB, 2 players) 6♦ 3♦ 6♥
Hero bets 22.6 BB, BTN calls 22.6 BB

Turn: (92.7 BB, 2 players) Q♥
Hero bets 20 BB, BTN raises to 173.7 BB, Hero calls 47.1 BB and is all-in

River: (226.9 BB, 2 players) 4♦

Hero shows J♣ J♦ (Two Pair, Jacks and Sixes)
BTN shows 9♦ 9♥ (Two Pair, Nines and Sixes)
Hero wins 215.6 BB