I gave it a thought but as I understand displacement maps, their depth resolution is dependent on the patch resolution so to get sufficient detail I'd still need way, way more than just four patches (times four) for each side.
Great suggestion, Robert! Thanks. I'm currently rendering a different camera move showcasing the lamps. I'll work on the pose of him leaning against the marble base for the end of the shot.
Here's a still of the lamps installed in the waiting room.