to make Bluetooth meaningful it must support high res codecs as AptX HD and LDAC. However, the only supported seems to be SBC in Volumio 3. Are there any plans to fix this and is there a way to hack this by myself in your Debain distribution?
Please do a feature request in the “Development/Suggest a feature” section.
This will bring this valuable feature to the attention of the developers.
There are plans for Volumio 3 to add Bluetooth as an output device, perhaps your suggestion fits into the plan.