It has the TM Unifi IPTV settings in the setup menu so will work. If you flash Merlin's FW you can get a lot more functionality - ad-blocking, additional malware/bad host blocking (skynet), etc.

I can't read Chines but in the screenshot you posted the title lists AC86U & AC68U but the top selection boxes are all AC86U as I read. Make sure you're buying a AC86U (not an AC68U).

It will work out of the box
But not adviseable for a few reasons:
1. Warranty nightmare. ASUS Malaysia does not provide support for units bought from overseas. If you buy from China, you will have to send it back to China
2. Smaller WiFi coverage. China has set a limitation on their wireless signal to be weaker than Malaysia. This is not something that you can modify with the RT-AC86U. With the older version of RT-AC68U yes you can change the region but not on ASUS newer routers.