I don't think the deliverance engine would be very useful, however the kostura cannon could be pretty devastating if they shot it just before their raid and jumped straight to a back line / home world. I've played a few mods that give the pirates the ability to capture allied ships and structures such as the new TEC support ship did before the nerf, a custom capital ship, a starbase on their base and even colonize other planets.

On a similar note it may just be easier to have pirate strength as another game setting Weak/Normal/Enhanced/Powerful/Despotic

what if the cannon was a combination to the kostura cannon and deliverance engine. When fired it would broadcast that the target is about to get raided = causing fear in the enemy while shutting down orbital defenses and giving the pirates a buff from the targets fear and unwillingness to fight instead of flee.