0 answer from OP. Useless thread.
I ended up buying the mini hip skirt, much cheaper on Renderotica than Renderosity. This mini hip skirt is as good as the (pretty cool) promo pic. dForce behaves fine as it is configured by default. Tons, I mean real tons ! of material options, damn well thought and organized. Definitely a cool skirt.
I'm particularly impressed by the really well made color and material processing for each of the 3 layers. Lots to learn from that bundle as a content creator too.