Some people complaining China Rom cannot access DBS Internet banking after doing the latest update. The risk seems to be too high nowadays to buy a phone with China Rom. Maybe flashing to global or other ROM can help, but as long as we don't know the bank security policies, we are also not sure if the banks will block phones with different ROMs installed. They might have a database on what ROMs are installed on what phones and disallow any phones which does not match their database. From a security perspective, it does make sense because no one can guarantee what malware is programmed into custom ROMs and where those ROMs are sourced. Even if it is a global ROMs, consumers also cannot guarantee that the ROM is coming directly from Xiaomi without tampering.