The opposite of "heaping upon" can mean a variety of things depending on the context. Instead of adding or aggrandizing, one might use words like subtracting, depleting, taking away, or minimizing. These words suggest a reduction, removal, or diminishment of something. They are often used in contexts where someone needs to describe a situation where there is too much of a resource, such as criticism or work. In other cases, one might use neutral descriptors like distributing or sharing, which are often used with resources that are not in abundance, such as food or wealth. Regardless of the context, the antonyms for "heaping upon" tend to imply a balance or moderation, rather than excess.