A sensor array turret would be a shielded turret with little armor that would serve two purposes. The first is to allow people with keys to always know the location and health of the turrets, and the second is to, by virtue of having a shield, dictate simply the minimum number of people necessary to conquer a station.

Because of its strategic value to defenders, setting its respawn time to two or three or more times that of the other turrets seems reasonable.

It would be cool if it gave people with keys in the sector radar extension and shared group radar too.

dictate simply the minimum number of people necessary to conquer a station

This is already the number one problem with shields in VO, and it should not be extended to station capture.