Hi again. It seems that "rfcomm bind all" isn't a thing that works in bluez 5.x, by design, so I think that the bug here as far as debian is concerned is that the init script tries to run rfcomm at all. You now have to run rfcomm <dev> <mac adress> for each connection individually, the command doesn't accept 'all'.
The reason my device doesn't work with 5.x seems more likely to be because it uses bluez-alsa and the bluez-alsa version in sid is still 4.x and not 5.x.
