Here's another option, use PCS1 first and unless the model is overly complex or there's something dodgy with the geometry it should be able to handle it in theory (that and hundreds of conversions prove my POV)...

Anyway now that I have a semi working version of PCS2 I go in reverse:
PCS2 first, then PCs1 as a "Hail Mary" tactic...
[EDIT]
Oh and I found something, even if you attached a light, once I opened the cob again in TS and resaved the model after cliking on an exterior light , then the grouped model again.
It appeared instead of being black like it was before... Weird.