I have manually added my old library files (.mod) to the new fp-lib-table under windows, no problems at all.
A couple of tings to remember is to use plugin type as Legacy, and set the environment variables according to your system:
KISYS3DMOD=C:\DropBox\KiCad
KISYSMOD=C:\DropBox\KiCad\modules
If you find it difficult to add the libs from the library you can edit the file manually with a text editor, the file is located in C:\Users\Name\AppData\Roaming\kicad.
Didn't try to convert anything.