Sure, I totally agree with you - in real life, we can really put a person in exactly the same situation twice. If we could, this whole free will argument would be a lot easier to solve.
That said, I do think the toy models are useful. Pretending we can do this experiment gives an answer to the problem I've never managed to pick a hole in (and tbh getting other people's input on it is the hidden motivation for entering this discussion):
If we could let you choose a beer, then rewind the universe - including all particles, forces, and known and unknown elements of cognition anyone might postulate such as souls and deities back to their starting position - then let it go again, there are only really two things that could happen: 1) you choose the same beer because that's what the universe was leading up to or 2) you choose a different beer despite the fact that all parameters of the universe known and unknown are the same.
The first outcome would suggest determinism; the second randomness, or at least independence from all variables which we consider "self" such as personality, memory and perhaps souls and things, since they were all rewound with the universe. I'd be really interested to hear of any third option anyone can think of!
As you say, showing this in a toy model isn't the same as showing it in actual reality; but when the actual experiment is impossible, one is arguing about abstract concepts anyway, and one has a lot of difficulty imagining outcomes not encompassed in the model I'm not sure we can do much better.
then I'll get bored and start fucking around with the system, and then I'll get really bored and stop cooperating with you. There won't be much of a convergence over time.
The problem with that model seems to be that as time goes on, the situation in which you are put in becomes increasingly dissimilar to the original one, just because of we've added memories of having had to make this choice x number of times before. If we could run the experiment so that you always felt like it was the first time you were in this situation, perhaps by putting the same kind of decision in different contexts and spreading them out over time and with various distractions, do you think you'd still deviate in the same way?
I know I'm going back from territory to less practical abstraction here, but I think this kind of difficult-to-collect data would be more revealing for this question.
The threat of severe punishment if one goes against the commands seems pretty similar to compulsion to me. If I commanded you to do something on pain of being thrown in an eternal pit of snakes, you could reasonably say I was forcing you to do it.
I would also be interested to know how C.S. Lewis separated righteous divine intervention from omnipotent busybodiness if anyone has the knowledge and a few minutes to save me from the terrible trials of actually looking up this myself!