The antonyms for the phrase "set large" can be "set small" or "set minimal." When something is set large, it means that it has been enlarged or increased in size. On the other hand, setting something small means reducing its size, making it more compact or concise. Similarly, when we set something minimally, it means that we are keeping it at a bare minimum, without any excess. The opposite of setting something large, therefore, is about making it small or minimal in size, quantity, or extent. Both small and minimal settings can be equally useful, depending on the context and purpose.