So if you click the download link for 3DXchange you don't get this:
Version 4 of the extension includes DUF files for G8. It's included with both 3DX Pro and Pipeline.
An FBX key is generated when you export from 3DXchange.
May I ask what you want to do? If it is using DAZ characters in iClone then an easier way is to import them into CC via the Transformer option. You will need CC Pipeline for that.