* Use an automation app (I prefer Llama https://play.google.com/store/apps/details?id=de.refluxa.and... ) to configure Bluetooth Auto Connect to happen when (e.g.) "screen on" and "wireless not connected", and configure it to disable Bluetooth Auto connect when "screen off" or "wireless connected." Add small delays here to avoid race conditions.
It all seems needlessly complicated, but the end result is that the device will tether if it is awake and cannot find wireless, and it will disconnect from the phone when it goes to sleep or when it does find wireless, which is exactly what I want.
