Hello PicoDevSupport, thank you for your answer.
I have the edited config.txt directly in 'Internal shared storage' folder in place.
But it don't loads my .apk on start, instead it loads the normal environment.
How to enable the factory-settings on Pico 3 Link?
On your docs, there is no info how to do that for the Pico 3.
On my headset (PUI 22.214.171.124), I have under developer menu only:
Also I tried to 'Press “Confirm” and “Volume Down” button together on the headset'.
This only lowers the volume, don't shows a 2D menu.
I compiled the Launcher-example in Unity, but without the kiosk-replace possibility, it don't helps.
By the way, I think it would be a big plus, if Pico makes the home-room moddable for users by using an open 3D format for it, like .gltf or .fbx instead using a closed proprietary something.
Keep up the good open source way!