The most possible way acausal trade turns out to be infeasible is probably like ascertaining that other party has decision procedure that is actually dependent on yours. And finding such parties, that would in turn look back at you.
Like, let's say the basic case for the trade is like that. You want A to exist and have B-suitable opportunity. You can make A out of it, but at 0.5 efficiency. Someone else has this situation but reversed, they want B to exist and have A-suitable opportunity.
You can trade and both will be better off. Of course even better would be the situation when you look like you are going do your end of the deal, but then not do it, you get 150% out of that.
So, you should do your end of the deal only if that makes the other party to switch from not-A to A, with enough credence that gain outweighs the cost.
But, how do you ascertain that? That sounds super difficult, and there incentives to be deceptive in the impression you give off.
Okay, here is one way to look at this.
Let's say there are large agents that you can't effectively simulate, because their policies depend on large fraction of compute you yourself have. But some of them were not always like that, some of them were small and then grew. You probably can exploit that? Like, you can look into them and see that they commit to become particular type of large agent. So, you can do actions, that their later self would be able to see, even if they can't now.
Small visible agent commits to something -> You in mid stage see them and do your part -> Small agent becomes large and able too see you in mid stage, and verifies your execution, and does its part too.
It's plausible a lot of this stuff demands very early commitments, and sprouts from that. Of course as you are small, you can make very bad choices, so you should do less choices. Unfortunately.
Also something something successor alignment.