...so how do you get UE to work in Poser?
Well, the way I did it might not be the correct way, but, I did it this way:
You get the DSON Loader script from D3D
Run it in Poser and locate the UE light DUF in the Light Presets folder and open it, this brings the light and sphere into Poser
What I then did was to apply the Kitchen HDR texture to the sphere and tweak the settings of both this and the light and used IDL lighting
As I say, that might not be how you do it in DS, but, it seems to work for me. I might try a specular light and see what that does.