Is definitely working outside of China my country is united kingdom CC JP,CC RU,CC US blocks 4g CC HK, CC IT ,CC CN those 3 enable 4g but not that to work you must have the fcc mod patch installed on the rc pro
With 01.00.1500 you need the fcc mod from the Chinese on the rc pro you need 03.02.0700 to install it first time then after the rc pro can be updated to latest firmware
Does not work atall on 01.00.1000 ino this because I had it also 03.02.0700 will not enable the 4g it has to be 03.02.0800 or 03.02.0900 on the rc pro aswell as latest firmware on the mavic 3 and to answer your question you can download latest mavic 3 firmware using drone hacks
Have to change the countrycode if you have the fcc mode installed on the rc pro CC US blocks the 4g dongle change it to CC HK you then have fcc mode and 4g