I would have expected 4 lifting points onto each side of the bag. These would basically by 2 bits of rope (from 1-2, and from 3-4), with stainless rings in the middle. The rings are then connected with another bit of rope, also with a ring in, and finally you attach a piece of rope to this ring which goes through a block at the spreader and back down the mast to a cleat. I can’t see how 2 attachment points on the bag is going to be enough.