Quote - Testversion Alpha 1.41, Download here 

This version has experimental skin and velvet support. Please give feedback after experimenting.

(1.40 is still downloadable from my footer if this version does not work for you).

SKIN:
Poser Skin SkinColor -> Lux mattetranslucent Kr
Poser Skin SheenColor ->  Lux mattetranslucent Kt
Poser Skin Thickness -> Lux glossy d
Poser Skin eta -> Lux glossy index

VELVET:
Poser Velvet Velvet_Color -> Lux velvet Kd
Poser Velvet Ka -> Lux velvet p1
Poser Velvet Kd -> Lux velvet p2
Poser Velvet Ks -> Lux velvet p3
Poser Velvet Edginess -> Lux velvet thickness

On the Metal Support (1.41) version we should follow this :
"Add a reflection-node as usual. If Diffuse_Color is Black the exporter assumes a mirror, else metal."

How are the "Skin" conversions created, do we need to have a specific Poser node or channel "on" ?
I run the script, it works like normal, but there is no difference in the lxm output.

On the"Skin" version should we do similar like the Metal.

Maybe it is due to Lux version .7, I cannot run V.8 because of OSX 10.6- Just a thought.