MQTT Lock - Battery Topic

Would love the ability to add a Battery Topic to an MQTT Lock so that it doesn’t require a separate sensor.

  lock:  
    - platform: mqtt
      name: "Front Door" 
      state_topic: "smartthings/Front Door/lock"
      command_topic: "smartthings/Front Door/lock"
      battery_topic: "smartthings/FrontDoor/battery"
      payload_lock: "locked"
      payload_unlock: "unlocked"
      initial: "locked"
      retain: true