Well I tested today the modded drone twe@ks app.
After it locked home point (gps) the transmision panel turned into fcc mode. (line above 90)
I sent it to 1762m without signal interference or losing signal.
as you could * enable it throught RC ( free hack which is not working right now), through drone firmware (drone h@cks), or throught the app (modded fly app) I quess that there are a lot ways to do that. I don't know if is the same result.
In Mini 3 pro there is no chance to convert to fcc after latest updates
edit:
I 've just bought a modded app dji fly which enables fcc every time it starts . Without connecting the serial port of the Dji - rcn1.,without changing the firmware of the drone.
Because there is something in the new firmware that is blocking the patch.
But I wondering How in some paid modded dji fly app is working without patching from the serial port before opening dji fly app.