You’re getting it confused China doesn’t have to do anything just sit back with a bag of popcorn and watch the United States put on a show.

It's like 6-7 CNY to USD right now. If that goes to 1 or 2 (if the CNY rises dramatically in price wrt the USD), then everything imported from China to the US explodes in price. Explosion in price, the imports reduce dramatically. So Chinese exports, which comprise like a quarter of their GDP, implode.

china won't want to drop the advantages of being able to have such tight control over the flow of yuan.

Maintaining control over capital flight from china, for example.