I'm getting confused. In some posts you say IDL (Indirect Lighting), in others you say IBL (Image Based Lighting). Are you using both? Although I suppose in Poser IDL is not a physical light, you make no mention of it in your first post in your light setup.

The renders look great by the way!

Daz Studio 4.8 and 4.9beta, Blender 2.78, Sketchup, Poser Pro 2014 Game Dev SR5 on Windows 8 Pro x64. Poser Display Units are inches