After which we can intercept the incoming OPP communication and interact with the input and output streams. Then I used reflection to access a method on BluetoothAdapter (code below) which allows listening on a specific port. The first step is to go to settings > apps > running > Bluetooth Share and kill the BluetoothOppService I believe I have (at least a partial) solution which should then allow files to be intercepted via OPP and custom code added.
