Just a silly idea for a wider metagame without changing much and focusing on adding extra motivation to the current gameplay.
My motivations here;
1) Don't make it so a casual player can be screwed over by the meta. Forcing people play in a certain way during certain times of day or granting one side a massive advantage would be just ugly.
2) Make it so the meta grants rewards to everyone, encouraging people to take an interest. An XP boost for everyone, even the casual player who might not be invested yet, is the best way I can think of to encourage people to become invested. Obviously this might need to be changed for more involved players, but at that stage the meta often becomes its own reward.
3) Make day-to-day gameplay matter. Having the meta focus around events that only make up a tiny and unrepresentative fraction of actual gameplay, or that require large scale coordination that disqualifies a substantial chunk of the player-base from taking part (or worse, means anyone not on the A-team for their faction is hurting by trying to take part) is bad. Good meta play should look like good everyday play.
The only new mechanic I would add is a continent/faction wide point system. Each time you gain resources from a base you also gain CCP (Continent Control Points) based on the size of the base and distance from your warpgate. I'm thinking the shortest distance along the new chain system times the base size (so double for medium, 4x for large facilities). Completely capping the continent grants a one time bonus of <substantial number goes here> CCP.
There is a fixed CCP cap. Once one faction reaches it for a continent an announcement goes out and there are lots of graphical indicators for all factions. A timer is also started.
After *X hours* there is another announcement and new indicators, and a new *Y hour* countdown starts. If the faction who reached the CCP cap can cap the continent during that period they gain a continent wide XP bonus (I'm thinking 50%) for the next three days, during which time they don't gain any CCP on that continent. During the period the other two factions gain boosted defensive XP (think double defensive bonuses) and increased CCP gain.
Tweak the numbers so that you have each faction hitting the CCP cap on a continent every 2 weeks to a month, leaning towards the long end. There are enough continents and factions that's already multiple events a week, on average.
As far as the capture timer goes, I'd say that 6-8 hours over peak times for that server would be right, with the prior countdown adjusted so it always starts at the right time. Also allows for staggering for different continents and factions reaching the CCP cap at the same time.