Re: I hate loose ends... (The Fall & Titan SPOILERS)
Federation did something nice of that kind - Cochrane got transported to the enterprise and assumed the teleportation method copied him and deleted the source, which obviously terrified him - before he was told that only the earliest prototypes did that.
Does raise some interesting and disturbing possibilities though - clone a genius to hurry a tech breakthrough during war, cloning battle experienced soldiers....
In defeat, malice. In victory, revenge.