Which version of Cycles are we on, anyway? Based on how PrincipledBSDF looked, maybe Poser 13 was 3.x? There were updates in Blender 4.0 and 5.0. Clearcoat became Coat, there was a Thin Film function added later. Blender 5.0 documentation here: https://docs.blender.org/manual/en/latest/render/shader_nodes/shader/principled.html