I’d like to discover alternative sources if you know any. Most written literature I come across in searches are either technical specifications biased from the Bluetooth consortium, or watered down blog spam of the same consortium’s news releases. Very little in terms of critical analysis or observations of user adoption and real trends in the original equipment manufacturers.

For example, all throughout the news releases of 5.X, no one would discuss if any improvements to bidirectional audio sinks for microphoned headsets were implemented or planned. It’s like the consortium is content keeping us all on phone calls with HFP from the 1990s at bitrates of 64kbps, leaving Discord audio sessions sounding like on-hold music at the DMV.

It’s so frustrating that mono audio+mic has been the norm for so long. The awfully small bit rate for both sink and source channels is just the cherry on top. I have to break out a USB-C DAC with a TRRS connector for discord calls on my tablet, as every manufacturer has done away with internal headphone jacks, just maintain the same audio quality I would have on speakerphone mode.

Android is also pretty frustrating and that you can’t bifurcate your audio syncs and sources. For example on any modern Linux distribution, you can at least direct apps to use your internal laptop microphone by default, and your headphones for full bit rate stereo audio only - to work around and avoid Bluetooth’s ancient HFP protocol. Why Android developers can’t replicate this basic audio muxing is beyond me, but resorting to a device’s internal microphone comes with its own setbacks.

Perhaps that muxing on Android is only possible for Bluetooth headphones without a microphone, but I can’t find any earphone devices that are not also headsets anymore. Just doesn’t seem to be a thing any longer.