As best as I understand it, the only way Chris could win on the break with the 8 is if he called the pocket before breaking. If it gets pocketed on the break by either player, it stays down (unless they have agreed to spot it).
If Appleton pockets the 8 either on the break or by combo, carom, etc, the 8 stays down and is no longer in play and winning that game on the 8 ball will not be an option for Chris. In your words it will "nullify" the spot for that game and the spot will not "change in anyway". If his spot ball is down, he won't get another in its place.
