Forum made a completely edgeless board years and years ago. It was marketed as a cheap board for hitting street rails with. It was garbage. The base and sidewalls got all torn up and ruined so fast. The metal edge is important to keep your board or ski from getting destroyed by minor hits I think.
The only real need for not having edges would be if you're trying to slide things like Will Wesson does. Aka picket fences and tenis court nets. Or I guess if you're exclusively riding deep powder you probably don't need edges.