Low SPR river decisions

This topic can be used to discuss in general low SPR river spots (let's say 0.5 or less).

So I posted this hand recently in my blog and ended up thinking about it more.

So few things from my side in SB:
- When I pot-call turn and leave this 33bb behind I basically announce I have draw without solid showdown component.
- River SPR in this spot is around 0.25 so very low
- Would I ever try to bluff in this river spot? Probably not to be honest as I expect very minimal fe. But this could be also little bit bad way of thinking as 9T is extremely big part of turn pot-call range. We need to have combo hand on turn to make this play and if it's set/2 pair+fd type hand we would likely most of time just shove turn.

So if we assume in BB shoes above thinking to be likely from SB should we find folds when unblocking 9T? He does have nut low straight blockers which has some blocker value though not that much. Issue is that if he starts to fold sets he does open door to be exploited I would assume.

This is very different spot in BB if SB is recreational type player as I have quite often seen weird lines from them with stuff like dry two pair. Where they bet-call turn and then lead shove river on scare card. Then you wonder if they were bluffing or not in their own mind.

But versus reggy player I could see fold being reasonable with some of our turn value raise range. You can of course argue that price is just too good to fold and make sure we don't end up overfolding.

But this does create questions:
- If you never bluff with SPR 0.25 in this spot in SB shoes what would be lowest SPR you would think of it?
- should we actually be more happy to call river lead shove with higher SPR in BB shoes versus reggy player if my way of thinking is the meta in player pool from regs?