While the DJI Osmo is amazing for smooth cinematic shots, when it comes to audio it is. well… lacking…. If you want to retain your run and gun portability along with good audio, there is a 3.5mm jack that you can use for external audio (of course you can always record the audio seperately and sync in post, but we are talking a quick run and gun setup here).
Of course the challenge is to keep the rig light and easy to operate. Aldryn Estacio of FlytPath shows a nice little hack that keeps the rig small, while providing pretty usable audio.
While this hack still uses the original phone mount from JDI, it uses the phone and Joby clamp as an additional mounting point for the microphone:
If you want a simpler/cheaper setup and are willing to let go of some of the flexibility, DroneTech shares a few simpler setups ranging from a $5 Neewer neck mic, to a $115 transmitter/receiver combo to the mentioned remote recorder.