I think I have a four player table solution that everyone will appreciate.
Why not set aside a certain time, say, six hours a week, where one of the two player tables becomes a four player table?
It would mean that people who wanted to play four-player games would have to coordinate, but it has the potential to raise site traffic here (having a four player itinerary board here) and traffic on GCCG will remain the same.
-wtk