One thing to keep in mind about the version for China/HK/Marco with dual physical sim version. Yes, you can have to sim card from different carriers installed and be active without waiting for eSIM to be supported by carrier. HOWEVER, the versions for China market do not support Wi-Fi calling feature due to government regulation. Meaning anything like Skype will not work with the phone, so as the WiFi calling feature provided by US carrier. Other than that, phones are essentially the same.
Even if that is true, the bigger deal breaker is China iPhones do not support FaceTime audio. Hong Kong phones no such restriction.