Enable audio over bluetooth on Kobo

[F5OEO]

XCSoar version

XCSOAR 7.40 - git c24da2f

What should XCSoar do differently, what functionality should be added?

Kobo CLARA 2E has a bluetooth chip. It could be helpfull to send audio over ble to have audio vario on an external speaker.

What are you trying to do, what is the use case for the suggestion?

I succeed in playing a wav file audio over bluetooth with alsa using bluealsa-plugin already inlcuded in original Clara 2E rootfs.
XCSoar is using salsa lib which mention "alsa-lib plugins and configurations are completely dropped". The ble plugin is thus not usable.

As XCSoar is compiled with static, we could maybe use alsa instead of salsa. However, the plugin architecture mentions "the external plugins are implemented in a shared object". This solution is thus non trivial.

Could it be possible to have some dynamic link library of XCSoar (breaking its static behaviour)
Any other suggestion to implement it ?

[MaxKellermann]

For the record: I'm not interested in spending time to make XCSoar dynamically linked on the Kobo (or spend time on this feature at all). If this is ever implemented, it will be somebody else, not me.
If somebody really volunteers to implement it, there should be an audio driver inside XCSoar which talks directly to the Bluetooth device, without going through ALSA. ALSA is just unnecessary complexity here.