To understand easier, need to put a clear separation mark between DJI drones ready to fly that need DJI GO (= v 3.x.x) and the others that need DJI GO 4.They claim their method doesnt work with P3
All the drones made after Phantom 3/3A/3P belong to another generation and they need also different procedures to do a custom set-up (Inspire 2, Phantom 4 series, Mavic series, Spark).
This is the reason because what can be done to PH4 and the others in the group, cannot be done, in the same way, to PH3, or cannot be done at all.