It's slippery, and I avoid using it altogether.
I've heard pretentious scientists use "metaphysics" as a slur to belittle the discipline of philosophy, and I've heard academics use "metaphysics" as a badge of honor to belittle physical science. Barnes & Noble uses the word to advertise something closer to "magic" or "alchemy".
Within an Epicurean context, the idea of anything "after-physics" seems unhelpful. After all, the Garden "supposes the study of nature provides the proper space for the voices of the facts."