I've bought IDL Light Rig, GI Studio, and also PhotoBox. And kind of formed the opinion that- that's just what light emitting objects do. Fake GI lighting in Poser seems to get a certain look, which sometimes is desirable.

Here's a quick render using the default render settings with IDL light rig. The reflector is located to the top left and the RimLightL and BG Left lights turned on, no SSS. The camera was located to my taste, of course. Like I said, it gives a certain look, sometimes desirable, sometimes not.