Bluetooth has a delay for most codecs. Do not ask me how it is exactly done but there is a feedback to the application so that it delays audio to match video for the bluetooth delay. Some years ago a new Linux audio subsystem was developed, and this thing did not work at start but they fixed it later. From that time is my memory.
Unmounting does not mean the device gets invisible. You could still mount it again by e.g. clicking it. Still it is unmounted and safe to be removed. Disconnecting the device from the system makes it disappear but that is not required for unplugging/ejecting.
This would be a flight mode switch that reliably works. But it also means you are offline, which is no solution to the average "daily" problem of being tracked.
As much as I would love to have a Linux phone, it will not fully help with privacy. The devices are logged into a cell tower and have a unique ID. This alone makes them trackable.
It is not worthless. My understanding is that management only trusts sources that are expensive.
Frigate can run as Home-Assistant addon easily. Then one does not have to manage / update the docker container.
The Home-Assistant integration for Mammotion works very well. It's a local integration and you can block internet access for the mower (and base station) afterwards if you like to.
Which version did you try? I used the 24.12.something version earlier this year for some rather complicated project and it was very stable.
I know they had stability issues before but not with that version. Disclaimer: I did not do video editing since, so I cannot say if the stability issues are back.