I ginally got around to make the bomb spawner into a custom module. Place the "zz_adder_BombsModule.prpl" script on any core on the map (place it only once, though), and place the "zz_robot_BombsModule.prpl" on a core that you place under a ShipSpawner if you want to make it work for NPC ships.
You can download the images from here (https://knucklecracker.com/forums/index.php?topic=26963).
Sooner or later i'm going to add this to a Map.