Backyard Door sensor template to show gate icons

I have an Aeotec dry contact on my backyard gate. I was easily able to change icon from a door to a gate but the icon stays the same, and only the color changes. I created a binary_sensor template to make the icon change based on the sensor state following these instructions:

… but I wonder whether there are other ways to do this.

The way I set it up I ended up with two entities:

binary_sensor.backyard_gate (the actual sensor)
binary_sensor.backyard_gate_sensor (the template sensor)

The template code is (please note this is in a template.yaml file so the template: declaration is in configuration.yaml file (mentioning this as noobs like myself won’t be wondering why the code is not working if they copy it… it got me quite a few times in my first weeks).

  - binary_sensor:
      - name: "Backyard Gate Sensor"
        state: >
          {{ is_state("binary_sensor.backyard_gate", "on") }}
        icon: >
          {% if is_state('binary_sensor.backyard_gate_sensor', 'on') %}
          {% else %}
          {% endif %}

Is there any way to tell HA that the binary_sensor.backyard_gate (the actual sensor) should use gate icons and should default to open / closed states without having to create a new binary_sensor?

EDIT: I “customized” the binary_sensor.backyard_gate_sensor (the template sensor) assigning it to device_class: door in my customize.yaml file.