Theoretically I agree with lumpher; but I would love to hear the details about how this goes. I think we do a lot of things just because that is the way it has been, not necessarily what is possible/good.
Why sweet? Do oats have only long-chain sugars that yeast can't eat?
Why foamy? Oats have a lot of oils that will kill head, no?
My only concern would be what kind of oats. If you used instant oats the starches would be partially converted already, so that should help efficiency.