Is there configuration to allow PushToTalk to have priority over Telephony or Facetime calls?

Is there the ability through configuration to allow PushToTalk (PTT) to have priority over Telephony or Facetime calls if the user desires that? In a public safety focused PTT application there could be times where the PTT application may be more important than a telephone or Facetime call to a first responder. In the perfect world a responder would be able to manage both telephone and PTT calls at the same time. For example, put the telephony call on hold during the PTT call or work both at the same time. Working both at the same time might look something like this: route outbound audio to PTT while the PTT button is held and route audio to the phone call while the PTT button is not held down. Incoming PTT audio and phone or Facetime audio could be mixed or one played in the headset and the other played from the phones speaker.
Thanks in advance for responding to this question.