After sending your ICE effect back to Maya, you can modify objects or add new ones to the scene. For example, you can change the location of collision objects, and then re-send the scene to Softimage to update the ICE effect. If you no longer want to use an object in an effect, you can delete it.
If you have made changes to an animated deformation, you need to update the geometry cache.
Maya selects the objects previously sent Softimage before sending the scene. Softimage updates the effect with the new objects.