I'm in Singapore. Some mobile phone stores here bring in the Hong Kong versions of the iPhones, which have physical dual SIM too.

I specifically searched for and bought the physical dual SIM version of the iPhone 11 Pro, because most of the MVNOs here still don't support eSIM.

Does the Chinese dual-sim iPhone have any restrictions or downsides compared to a US or EU model? I might consider it as my next step if I can let go of the iPhone 8 and its fingerprint sensor.

I just looked through my iPhone's emoji keyboard and it doesn't have the Taiwan flag: https://www.bloomberg.com/news/articles/2019-10-08/apple-pul...

If I used it with any regularity, I could probably work around it with a keyboard shortcut.

Which region are you in and which region is your system set to? I always thought things like this were determined by which region you select when you set up the phone (or something similar like detected via GPS/network instead of being bound to the hardware itself).

Singapore, with Singapore SIM cards.

I have nothing that links to Hong Kong or China, so it's probably implemented by identifying the different phone model number of the dual SIM iPhone.