ACBC's automatic Calibration Concept section is programmed to show the following concepts:
2) "Not a possibility" concept
3) A "winner" from the tournament
4) A "loser" from the tournament
5) (Repeat pattern of last three, if needed)
6) Winning concept from the tournament
You cannot change its behavior. And, because ACBC does not have capability to estimate "scores on the fly", you couldn't self-program it to behave like you want.
Why not just use ACBC's Calibration section as it is? It asks for purchase intent about a wide range of product concepts (in terms of expected utility). We believe it works well as already programmed.
And, asking only 3 calibration concepts doesn't give you a lot of information from which to estimate a "None" threshold. I'd recommend five or six.