Double headers wouldn't work, Just try and imagine two different teams trying to use the one set of change rooms on the same day....
Unless of course the SANFL is going to build extra change rooms at selected ovals, then the other ovals would want a equal ammount spent on their facilities as well, good Idea but impractical.
I would only be interested in watching South play, if there was another match after Souths time slot, then I would go home and do something else.