I am trying to get my head around this and it seems the more I experiment the more confused I become.
The one conclusion I've come to is that whilst it would be a nice little feature, including Rag Doll at this stage is not vital and as I improve the rigging of my game characters and with the export pipeline through .fbx working very well for me I am sure that I can come back at a later stage and add it.
Maybe Helghast will have some kind of plugin kicked out by then too.
Either way its certainly given me food for thought...
Cheers all