I am using this as an alternative for OnTriggerStay because OnTriggerStay is expensive. I have room colliders that keep track of if they are actively colliding with specific spawned game objects. When the other game object that is within the room collider gets disabled I move it off screen first so that the room collider's OnTriggerExit gets called and then I disable that object.
Its okay if killables wont work in this situation. I have an alternative method I can use as well.