xiaoxiao this page is not a reply to this thread. It is just an abstract from the user manual.
Thing is that the smart route does not work as advertised. also there is no smart if you have to configure every page or ip with a rule.
In the FAQ page is mode it says:
DPN Smart Route automatically distinguishes the region of requested network content and controls which tunnels should be used to access the content
this is is not happening, the device needs a rule for every page you need to go through DPN