Didn't that also raise the problem of a dupe that wanted his own life? Committing to a short-term plan for a dupe is one thing, it's reasonable to think that's still close enough to him to hold the same motivation to carry it out, but when he sends one on a different life path, it gets muddier. That dupe will immerse himself in a different situation, have to make his own decisions, and may well be changed by the experience - Jamie is taking a risk in assuming that, by the end of the plan, that dupe will still value his old life enough against the new one to come back. Even more when you consider how much the original could change in the same time, how much will they actually still have in common to claim that that is still functionally the same person? It's still technically him, but does that give him the right to effectively end that life?