I like the idea of a kind of hidden forum, not necessarily for questions but for research.
It would go like this: Anybody can get admittance but they have to accept a terms of usage agreement that states that if they want to take advantage of the research being done in this forum, they in turn have to post any relevant (and I see that this term would have to be defined) discoveries they make in this forum. Mod teams can also join as a whole thereby agreeing that they will share their research work.
The problem with telling the public about something you research is that everybody can immediately take your idea and do with it whatever he wants while he in turn can keep all his small secrets to himself - thus, if everybody would share every scrap of research publicly we wouldn't need such a forum, but as it currently is, there are some kind of "trade secrets" where mods/people keep discoveries to themselves (and I am no exception to that).
Another issue with doing research at all is that it takes a lot of time and any team you are affiliated with doesn't profit from it more than the whole community. And as everybody cares for his "tribe" more than for "everyone else" this makes you sometimes develop a guilty conscience if you just spent 10 hours on research in which you could have been modelling/scripting (my own experience btw).

And a lot of advanced modding questions/discussions indeed happen through chat because conversation is just more natural if you use such a medium instead of a forum with the added advantage that you don't have any third party taking advantage as mentioned above.