Just stumbled across a security option in Android called "pin screen" (finding a way to make my phone safe for a toddler) and thought it would be awesome for Dji go.
You can pin/lock an app to the screen making it impossible to accidentally exit the app, it also disables notifications and incoming calls.
If you Google "pin screen android" you'll find heaps of tutorials to get it working.
I know I've accidentally escaped out of dji go app while flying and it's a bit of a pain.. This should prevent that happening.

Anyone using this method already?

Yes, I use it frequently. Mainly when my daughter wants to play a game on my phone. Works perfectly to lock the device to the game screen. Never thought about it using it with the DJI app, but it does make some sense to use it.