U.S. ratification of UNCLOS won't help pressure China to change its position in the South China Seas

I understand the force of this argument. The U.S. already adheres the key principles in UNCLOS, so joining UNCLOS will allow the U.S. to push back more effectively against China’s aggressive and expansionary activities.

But is there really any evidence that formal accession would change China’s view of the U.S. position on UNCLOS issues?  China is already a member of UNCLOS and other countries (like Japan and the Philippines) are also members of UNCLOS. But I don’t think UNCLOS has really bolstered their effectiveness in pushing back against China.  Moreover, as Professor Dutton explains, China has a radically different interpretation of its authority to regulate foreign ships and aircraft in its Exclusive Economic Zone under UNCLOS.  How will joining UNCLOS help the U.S. change China’s interpretation of UNCLOS?

As a practical matter, UNCLOS does have a way of compelling member states to conform their interpretations: mandatory dispute settlement in the International Tribunal for the Law of the Sea or in Annex VII arbitration.  But as China and Russia have demonstrated in recent years, these mechanisms are not likely to be a serious constraint, especially on questions that touch sovereignty (which is how China frames most of its activities).  I suppose if the U.S. joins UNCLOS, and subjects itself to UNCLOS dispute settlement, that might make a difference.  But I don’t think it would be a very large one (after all, Japan, China, and the Philippines are all already subject to UNCLOS dispute settlement, which has accomplished little so far).