0 degrees would be a bit of a struggle to keep meat frozen most times of the year, things like outside temp and opening would make it hard to keep meat on the fine line. Our 50l is a older model and it just has a series of led lights as a temp guide, when we want stuff to stay frozen we get all leds going. So yeah I think you will need to set it around -5 degrees to keep meat frozen in all but the hottest months.
Ideas are more powerful than guns. We would not let our enemies have guns, why should we let them have ideas.