Add timer to debriefing screen until new game starts (or server shuts down, if its set as such).

That means unless you have people constantly manning bases (there is alot of them), you will loose them.
And you only have theoretical 64 ppl at best, while defending AI is hardly a challange.
This will only create alot of base back and forth
Take lose, take lose, take, defend, lose another one

These long capture times when you build anything, coupled with time and cost of respawn (10sup, so even stock base warrants 50 respawns), makes it impossible to cap bases.
So strategy to hold the base atm is:

1. Take key points,
2. Build as much as you can on them
3. Have 2-3 players (defenders respawn) and try to do at least 1 for 1 trade, there is plenty of time to interrupt the timer
4. By the time your spawn protection wears off, you already get enough supplies back to respawn again.
5. This will stop any attack