Good questions.
I have a cell phone and I do use it with discretion. I did buy a hands free device but I still have to pick up the phone to answer and disconnect. I wonder if that is considered an offense as well?
If it is then any controls - heater, windows, turn signals should be equally considered a “distraction”...
Are you sure the Bluetooth device doesn't have a button on it to do just that? I bought an earpiece at Big Lots for $13 with the remote connect/disconnect and it works just fine.