I would like to propose Corona Null material, that once assigned to an object, it would completely eliminate it from scene, as if it were hidden. Such material might not be useful on its own, but in combination with new the Corona Select material, it would become very handy scene management tool. Yes, i'm aware that one can already achieve same result with regular material and zero opacity or with empty rayswitch material, but this still degrades scene performance and thus is not ideal solution.