Would you be willing to provide me with a Bluetooth Explorer (an Apple dev tool) log from the time this happens? This should provide some more insight into what happens on your machine - and how it differs from mine. I could also forward it to Apple Engineering (as a bugreport) if I can't make sense of it myself.

If that's something you'd consider, please contact me at felix . schwarz [a] iospirit com.

Thanks in advance.

Best regards, 
Felix Schwarz