mSBC does not work with BCM20702A, nor with Realtek-based device in ALT-1 mode

hi,

i was excited to try the latest pipewire-git with my Sony WH-1000XM3 and my ASUS BT-400 bluetooth adaptor. unfortunately the headphones do support mSBC but the adapter does not. see here:

https://support.plugable.com/t/unable-to-get-hfp-wide-band-voice-aka-msbc-aka-wbs-working/19629

perhaps a wiki could be provided of chipsets that support HFP 1.6 16Khz?

i believe that some Realtek ones do, for example.