The knot was almost humorously small to me as I started climbing on 11mm ropes, and it looked tiny even compared to knots on a 9.8 mm. When I fell with little slack out, like while hang-dogging ...

The Mule Knot (a.k.a releasable knot) is ideal to lock off the rope on the belay plate. There are many occasions in climbing when, belaying from the harness using a device which does not self-arrest ...