Thanks for the encouragement as well as your earlier tests.
Realistically, this may take a while to fix. The problem may be related to an underlying library that the plug-in uses. The THETA V/Z1 use an Android OS inside the camera. The problem with the library may only surface when someone is live streaming from an Android device to YouTube AND using that library.
Laszlo is in the process of submitting his plug-in to the store. However, his plug-in likely has the same audio issue streaming to YouTube. His plug-in works to his own service or Facebook, but not to YouTube. His service looks good, but I understand you want to stream to your subscriber base on YouTube.
Also, you may need to blow a fan onto the body of the camera for longer streaming sessions.
You have an interesting use case. A few years ago, RICOH developed a specialized streaming camera (max 2K resolution) for this type of use case.
RICOH R | 24-hour live streaming 360 camera | Comparison with THETA
It worked with the Teradek VidiU
YouTube 360 Live Streaming with the RICOH R Dev Kit and Teradek VidiU
As it’s 2K only, the RICOH R may not be a good solution for you. Actually, I recommend you don’t spend more money at the moment. If I were you, I would wait and see how the plug-ins for your existing camera to evolve.