Make balena sound appear as a bluetooth headphone instead of speaker?

Hi, I am trying to pair a raspberry pi with balena sound to a Fire TV Stick 4K. The Fire TV Stick does pair with a headset to play sound and balena does pair with a PC and play sound from the PC. So bluetooth is generally working on both devices. Still, balena sound does not appear in the list of available bluetooth devices on the fire TV Stick. My guess is, that the Fire TV Stick only shows bluetooth headphones / headsets but not bluetooth speakers: Is there a way to configure balena sound so that it pretends to be a bluetooth headphone instead of a bluetooth speaker?

You’re correct that the Fire TV Stick likely only supports Bluetooth headphones or headsets for audio output. To make balenaSound appear as a Bluetooth headset, you could try the following:

  1. Modify balenaSound’s Bluetooth profile: You may need to configure balenaSound to advertise itself as an audio sink (A2DP) or as a headset profile (HSP/HFP). This might involve editing the Bluetooth settings or profiles on your Raspberry Pi running balenaSound.
  2. Use Bluetooth Audio Receiver: If direct pairing doesn’t work, using an additional Bluetooth audio receiver between your Fire TV Stick and Raspberry Pi may help bypass this limitation.

Hi
Using Raspbian and LibreElec I have been able to confirm that the BluetooClass of device determines wether the Raspberry Pi shows up as a Bluetooth device on a Fire TV Stick:, e.g.
Class 0 (default) does not show up
Class 1044 (0x0414) Loudspeaker shows up
Class 1048 (0x0418) Headphones shows up
So my question boils down to „Where/How can I configure the Bluetooth Class of Device (CoD) in Balena Sound / BalenaOS“
Unfortunately I still haven’t found the answer. Generally, the Bluetooth Class of Device is configured in /etc/bluetooth/main.conf.
But how can I configure this setting in BalenaCloud ?