No it doesn't answer the question. The figure on its own under direct light works as advertised (gamma set to 1 on transparencies), but in the room scene with the same settings I get the harsh smearing. It is not working in that situation. I cannot change the lights as the entire scene is illuminated appropriately for all other components, and lighting the hair directly would indicate back light that is not there, so his head would look wrong.

I don't understand what the blender node is doing; I did try disabling it but it made no difference in the render. I'm not sure if I could rearrange the existing nodes to a more basic arrangement without the blender node.