I don't know about adding cream. Or any oil (including fats, such as butterfat). When I make maple syrup, just the amount of cream that sticks to a toothpick is enough to drop the boil foam. On some of my hefe's, the head is -- well, the whole glass is head. Same deal, as little as it is, just dipping a toothpick into cream and swirling that around the top of the head is enough to collapse the head completely, within seconds, and no more head for any beer int the same glass until after the glass has been washed.
Like I said, IDK, I know there are plenty of additives to reduce foaming/boil-over, and some recipes (at least one I've read) advocate the use of a drop or some such amount to the boil to prevent boil-overs.
Anybody? And congrats on the beer! I wish you success in the competition. Just a thought, though - since it was/is already a terrific recipe, why mess with it?
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Secondary: Apfelwein, Chambourcin, Blackstone Pond American Ale, King of the North, Concord, 2nd wine from pulp of both
Bottled: Bavarian Hefeweizen, Dortmunder, King of the North (2010), Apfelwein (2010), Lesser Wilderness Mead (2010), King of the North (2nd wine - 2010)