The chinese or anyone can copy the patent since it won't apply...

The chinese or anyone can copy the patent since it won't apply to the rest of the world. However, whatever they produce from it will stop it from being sold in the US - still one of the biggest economies. At the very least they can file an injunction to stop the 3rd party product from being sold if there is a possible infringement -ie delay it until the court case settles.

Apple killed the Samsung Galaxy Tab by doing just that. Delayed the roll-out. I hate Apple for that reason since they claimed to have invented the Tablet - the concept was around for about 20 years before Apple created the iPad. Nonetheless the lawsuit was lost by apple but it cost Samsung 000' millions in potential sales. There was another case where Apple also won because Samsung really did infringe on Apple's IP - $540M awarded.

The other effect it has is that 4DS can grant rights to a 3rd party to use the IP and get royalties from it. It is no different from using a Disney character on your product.

So yes 4DS needs to file all these patents and continue to file more patents when applicable.