I know this was prolly answered in the post. Have not had a chance to read it all.  What light types work from poser to Lux?  Not sure where to insert the sun parameter into the lxs file.
LightGroup "sun"
LightSource "sunsky"
   "float gain" [0.050000]
   "vector sundir" [0.965955 -0.026948 0.257303]    "float relsize" [1.000000]
   "float turbidity" [2.000000]

Great work on the exporter and thank you.