Ahhh I understand that you're looking to add to Firebug an ability to inspect the entire structure of a Spine application?
That would be fantastic.
Sorry for not understanding what you were getting at. I don't know of a programmatic way to get at the internals. Based on my current knowledge, I don't think so... but other Spine users may correct me.
If there isn't a way currently, I would be very much interested in offering any assistance if you'd like. I'm reviewing the information at the link you provided.
Alex