The simplest way to "fix" that is killing the original one as a required and atomic part of the process. Make it so that there is no moment in time when both are awake and concious
But that is still asking people to get into the death box so that a clone of them can live on. Personally, I wouldn't accept certain death so a copy of me could live.
But that is still asking people to get into the death box so that a clone of them can live on. Personally, I wouldn't accept certain death so a copy of me could live.