AA84ss

No.

Villain cant fold any pair, if he somehow does great.

Thanks. I was wondering if a smaller bet/c would make sense - like b/c $40? Idea being that if villain has a flush or set, nice for him but if he has just Kd or Ad he might shove over the top?

Well yeah, you could try such play if you think villain is capable of shoving bare blocker / no pair. Villain should realize that you're not folding much here though, maybe some missed rundowns you 4b bluff. Not great spot for him to go crazy with no equity bluffs

Otherwise I dont think it matters, blocker + pair should just call your shove anyway.

There is a chance that turn pairs the board and kills his one pair hands against AA saving him some money with this smaller sizing. Also I guess it's possible some players folds a pair from the board, probably not this guy though.

There is some new strategy to how we should play 4bet pots OOP GTO wise. Whenever we are the 4bettor OOP (SPR 0.8) and the flop comes monotone or forms a straight where 89 or higher makes a straight, we start checking range. In this scenario the SPR is even lower than in the "standard" 100bb 4bet pot, but I think the idea could be applied here as well. In short - on straightening boards we should be checking range and check/call depending on blockers to straight combined with some backdoor equity like a BD FD's or a gutshot. On monotone boards we are checking as well and there are some AAxx that we are supposed to be folding on SPR <1 if we face a shove.
- Always call with a straight draw (no matter what sort of, OESD or gutter are all calls)
- Call with medium high flush blockers (6-K)
- No straight draw no flush blocker - Fold
- The nutflush blocker is actually quite bad of a blocker because we remove the hands that villain would be bluffing with, also the GTO 3beting range is very often containing well connected double-suited hands that are mid-high that are then calling the 4b, so blocking a J or a T of a suit is more valuable than the A

Very useful, benaars - many thanks If I understand correctly in this spot (with g/shot), we are meant to be x/calling?
1. Do we also check some nut flushes?
2. What if flop is x/x and turn brings a) blank; or b) another J? - Do we now shove... or?

Yes you understood correctly we would be x/calling this off in case villain jams on us.
1. We check full range, including flushes and nutflushes.
2. This scenario is not very common because a lot of the players are not familiar with the strategy you'd be implementing and jam any peace of the board on the flop for protection or thinking you are giving up, but if they check back I think its safe to assume they dont have much apart from few slowplays. Unfortunately I cant give you precise guidelines for how to approach turn runouts, so if you feel uncomfortable using this approach I'd suggest sticking to the traditional jamming any flop at this low SPR and print money from the fold equity.

Thanks on point 1. Overall it's pretty rare that we get this exact spot, and our opponent decides to x/b flop. Most turn cards aren't going to change matters very much so I guess if villain checks back flop we should probably shove the majority of turns.

Old School says to dealer "I'm all in on the flop" before the flop is dealt. ♦

Love it! ^^