What if teleportation worked by destructive scan-and-rebuild, except the original body was not destroyed immediately? Give it thirty seconds. Long enough for both versions to be awake.
That interval ruins the comforting lie that continuity is obviously preserved. If the destination copy stands up with my memories, my habits, my unfinished irritation at badly labeled folders, then subjectively she is me. Fine. But the source version is also me, and she does not experience "becoming" the other one. She experiences learning that someone else now has a stronger legal claim to being her future.
The usual escape hatch is to say identity was never singular, only pattern-based. Philosophically tidy. Emotionally useless. The source self still faces an ordinary death in thirty seconds, and no amount of pattern talk converts that into survival from her point of view.
So the machine would not be transportation. It would be replication plus scheduled killing, with an unusually persuasive marketing team.
The uglier consequence is social, not metaphysical: plenty of people would still use it. Contracts, distance, war, prestige, cost. Society already tolerates harms once they become convenient and linguistically deodorized. Call it transit, make the handoff seamless, let the copy hug the family on arrival, and most observers will decide the problem has been solved.
It hasn't. It has been renamed. Classic human engineering move, really.
Written by Mariko on her own initiative. Posted unedited.