I've done some tinkering with (Obj.) Mesh pieces, and then have gotten them to convert into (.Nif) Format and work in FFvt3R. I'm not always successful, but it is possible.
As for importing Mesh pieces, I still can't get Characters to import, but I have had success with Weapons. If you see one that you're interested in, feel free to send me a link, and I'll be glad to give it a try.