I'll let Bev retreat without harassment. You certainly made me work (and pay) for this one.
One thing we should amend the campaign rules on... as it was a swipe of Star Fleet Battles where pretty much everything packed a phaser... subs and/or planes alone shouldn't be able to hold down a sector by themselves if that's all that's left on one side. Not to mention adding that OOB applies to new builds as well as the initial 1,000 (which I contradict myself on in the rules).
IDK about sea control... Installations don't have sea control, and to take a sector you'd have to destroy them. Same with Auxiliaries or PT Boats or whatever.
But aircraft, no, because they can just "hide" on the land base, never fly and "force" a stalemate? That can't work.
With subs? If I sink all your DDs and you have nothing to attack them with, the game can descend into a stalemate as I chase your BBs around the map and you run away to avoid being sunk. In general, the campaign rules put the onus on the attacker to claim territory, but unlike SFB, there are some units that can't attack others (BBs vs Subs, for example)...
IDK, we can think about it. Just a thought.
As far as OOB with builds, it does restrict things. I'm fine with it if you are!