simple answer: loop.
while the train is circling, you can start untying the people as they are resurrected. the real question is whether the train is slow enough to get the time to untie those people between each pass.

The top choice is better, because if you add up all the people killed, an infinite sum of integers, the answer is -1/12. Way less suffering than the second track.

They won’t get used to it because they keep dying and thus are incapable of holding on to any memory, experience or change.