I&J you can still catch elf on a spinner (spoon) once the sun has gone down. If the guys have been throwing ABU (Seriola) spinners, best to throw for distance especially if spinning in windy conditions, once the sun has gone down they may change to a spinner with more of an action therefore giving off more of a vibration.
These vibrations are then picked up by the fish, you can expect a slower strike rate but you will still catch. You are right though there are days when they will go moggy and I have had quite a few eat a plug on the surface, just wish they were a better class fish here in False Bay.