Seems odd that I can fly around in a Serco owned sector of Deneb system without running into at least some sort of NPC patrol. I would think that both sides should maintain at least a small presence in the sectors that have been claimed. This could then allow for player initiated skirms. Something like a small timed fighter skirmish to start. If the player fails to destroy the patrol in a given amount of time then reenforcements could arrive then after another amount of time it would escalate to a small skirmish, then medium, then large if the player fails to capture the sector in time. The timer would start when combat starts and the sector could "cool down" in stages if the player leaves and doesn't return for a certain length of time. If the player manages to kill the patrol in the given time and then hold the sector for a few minutes the sector could revert to the nation of the player.

We've planned to do something like this, basically where a sensor satellite would report your presence, and a patrol would come in to fight you off as a result, allowing this kind of at-will escalation. I still think something like that is a good goal.

I need to re-approach some of this in the context of what will make sense for conquest and holding of totally open space in the expanded universe, and how I can merge those mechanics with border-skirmish type stuff most effectively. But regardless, there will always be value to player-initiated conquest situations.