I've seen cold-steeping for both grain and coffee as a way to reduce harshness, which I'm assuming is closely related to acidity. Adding at the end of the mash is often used to extract more color than flavor, although I had always thought that was what Sinamar, Carafa and Midnight Wheat were designed to do. I guess I differ from the previous posters in that I would rather weigh out 1 cent's worth of baking soda and mash everything together than deal with a separate steep or whatever. But having only tried the one method, I can't say that the others don't have their merits.
Say no to intolerance: love gluten and lactose.