Gamespace uses an older Milkshape DLL for exporting. So it can export what Milkshape could export at that time.

I don't think that Caligari will write any game-related exporters on their own.

I also used to be a Gamespace user. I loved modelling with that tool but hated animation and texturing. So I changed to Lightwave with the result of a much more powerful and stable software with actual mdl7-exporters and exporters for other game engines as well.