It's not nice, but I'm check/folding. We have BW blockers but this is a pretty bad flop range vs range. The SPR (if I've kept track of everything correctly) is too low for villain not to go broke pretty wide here, but even at that we're in trouble pretty often WRT equity.

I don't mind the above advice about check folding, as it's likely what I would do in game. But I think the thought process sucks as we definitely have a range advantage. As far as GTO is concerned, a Bu flat of an mp 4 bet with (jt,kj,kt,kk,jj,tt,aq,q9) removing the seven known cards (As,Ad,2s,6d,Js,Kh,Td) occurs 16.5%. Human at this level, are going to be wider than this and are almost certainly 3 betting more KK than a solver is. However, I don't think its going to be enough to consider check folding imo. I also don't know of any regs that are going to be fucking around in this spot. If my math is correct, he has 129 behind on the flop and the pot is 72. I actually love a bet of $15 on the flop. I can't see a single good 100 player who is raising anything other than AQ and of course you have that blocked. I would then tend to ship any queen or spade, say "shit, what do i do here?" on an ace, and then for the rest of the deck besides a K/T/J I like betting small again such that we can set up a bet to fold out all hands we lose to but kk+ on the river. $25 sounds about right as that leaves us with a bet of 89 into 150.

I think betting small is the way to go here and obv fold to a raise. you will fold out all the low rundowns. I would fold against a raise ofc

if we look at the 100bb bu vs mp solutions, has all kinds of ds AQ combos; KKAQ, all the AKQx (except when x=6,7,8 those are 3b/folds) , then AKQQ, AJQQ, ATQQ,A5QQ,A4QQ,A3QQ, then AQJT, AQJ9,AQj8, AQJ5,AQj4 some AQJ3 and AQJ2 and AQJTss with high suit, but this is just the nuts, he has much more second nuts, sets, two pairs in his range than us, actually oop we should have quite a few of those also in our 4b range from MP but population has mostly only AA (with some Q in it certainly), so I expect a very high checking range here, close to full range (especially because it s a rainbow straight board)