"A smart person with the right access can see that", so like a store employee glancing at your choice of an analog temperature display or a telltale light? A perfectly workable solution that persists for the vast majority of the restaurant industry and every independent grocery store in the country, and has done for roughly the last century. Adding the kind of aggressively stupid failure modes that software drags into the discussion (eg. russian bot networks are attacking the ice cream) to avoid having to occasionally inspect equipment doesn't seem particularly bright.