Rotating Starting Positions.
Every month rotate the starting positions of each faction. This will give all the developers even more replay value for all the energy/work involved.
Things will be fresher for longer for each player, as the approach to certain areas and targets will change, the map will be more dynamic not less. It'll be longer before the been there done that feeling kicks in for each, so you extend the subs.
This is to add abundance to the already varied and detailed zones that have been displayed, and make no mistake they are abundant from what i've seen already!
The addition is what I always pictured doing if I ever coded my own version of what you have made, as it keeps things changing.
Hope it helps.