On player craft things may be a bit more problematic, as you can select only one target at time.
But perhaps SDK allows adding more buttons to the interface, like "Active turrets" and "Deactive turrets" and then the player handles the main guns himself or issues orders to use them for tactical while independent turrets takes care of hostiles in their arc of fire and range.
Adding independet turrets is possible, it is used on space stations, another question is that can you have any control over them even when you have the SDK?
By the way, SDK is coming soon.
