I was back it again this evening and tried several of the recommendations with no luck.
ronr -- those where the exact steps I took. Even with my dimmer set to 0 and a fade time to 30 sec, it snaps to a black out. No slow fades.
John -- could not find any snap or cross fade feature on the Magic 260 and nothing is mentioned in the documentation.
Since we open the show this Friday. I have trained the operator to use the master fader. I'll keep looking for an automated solutions. Let me know if you have any other ideas.