Of course you don't need it, it just looks a bit Russian then...
Sure it’s finished! Lawn edges/any kind of edges are the enemy of every lawn robot, and not because it gets stuck, but because then I have to do manual touch-ups there. I’ve already had the lawn robot in the ground-floor rental apartment with 100 sqm of lawn. Despite a flush terrace to the lawn, I always had to manually trim afterwards. So lessons learned, since I don’t feel like reworking, no lawn edging stones in the garden. ...although that’s not entirely true, on the left in the photo along the path it can’t be helped, no flowerbed fits there, otherwise there’s a “Russian” flowerbed all around the L stones at the bottom.