I’ve never seen that. I don’t think it would work. In this case he is not protecting against a shock load, he is pretty much ensuring a constant force on the an

I’ve never seen that. I don’t think it would work. In this case he is not protecting against a shock load, he is pretty much ensuring a constant force on the anchor by tying the ladder tightly and directly to the anchor. Climbing anchors need to withstand extreme loads as you could fall tens of feet before your fall is arrested and you load the anchor, plus the substrate is usually more strong than brick and mortar so you can make a much tighter (higher pressure) insertion before the wall crumbles.