This loop is like a Capstan knot ABOK 1831. I have tested it at 6 mm polyamid rope. Sometimes it slip under heavy load, if the "base knot" is tightened weakly. Sometimes withstands up to break. If the loop has not shrunk, the knot can be untied by fingers.
In my mind this "mollusk loop" is less complicated than a Capstan knot. It can be tied by one hand like a bowline.