Actually I kept wanting to use my phone (which has a headphone jack) as a bluetooth receiver for audio from the PC, and remember attempting to spelunk into the

Actually I kept wanting to use my phone (which has a headphone jack) as a bluetooth receiver for audio from the PC, and remember attempting to spelunk into the bluez stack (for use with lineageos) and getting frustrated quickly. There's some niche usecases (e.g. lengthy video editing on a PC while wanting to move around listening to music on your phone - airfoil (wifi) technically works but at the time was a bit laggy).