This shield does not directly protect your hull. It is shaped sort of like Bastion and it can be switched on and off. Instead of having a cooldown, the shield regenerates while it is off. For the sake of balance, the shield could have a delay before it switches on or off. It could also cost durability just to put it up initially, and you could be unable to switch it on unless it is above the durability threshold. Modifications to shield cooldown affect the regeneration of Aegis.