Hi - using osmo+ in aircraft cockpit. Due to cockpit noise, I need to disable the internal mic and enable the external mic. Idea is to have headset audio only as (lin in) input to external mic. In dji app, I see Mic Control, Sound on/off option. This turns all audio input off. Any help is appreciated.

I've experienced similar issues.

When you plug in an external mic, Osmo automatically sees it and disables the internal mic.  The audio meter on your screen should then say “EXT”.