It is downgradable but you will have to put a bin fil on your sd card.
It didnt help me tough
Bought a dji phantom three standard a few months ago and flew 60 kilometers without issues, but then i got a problem with my homepoint disorientating itself during flight, so i looked it upp on the internet and found others refering to the same problem while using the newest software.
I also noticed that I lost about 70% of my range due to wierd controller signal lost that i didnt have before.
Therefor i decided to downgrade my: 3.1.2 app and the 1.8.10 firmware into: dji go 3.0.0 and firmware 1.7.90(trough sd card).
Now the homepoint is stable but the signal lost remains.
The remote controller status bar is sometimes jumping from full to zero while hovering and angeling the controller as shown in dji's manual.
I have tried different locations with low interference.
I have tried relinking controller.
I never had an error uppdating firmware.
I newer crashed or damedged the controller or aircraft.
I have tried different android devices.
The problem also remains when i fly the aircraft without conecting to wifi but then i get a slightly better range but still not as good as i used to.