Shelly Dimmer 2 attributes are not exposed, am I missing something obvious?

Using the latest version of HA, and the standard Shelly integration. It’s working fine, without any problems changes in HA sync to the shelly and from shelly to HA correctly.

I’ve several Shelly Dimmer 2 switches which are all working correctly. I can see those switches on my HA UI, and if I manually change the brightness via the shelly directly I can see the brightness slider in HA adjust in real time with the same values.

I am trying to achieve a new automation that will toggle an input boolean if somebody changes the brightness level of a light once it’s turned on, but am running into problems as it appears there is no way to reference the existing brightness value (or, I can’t find it which is more likely)…

Via developer tools -> event listener I can see the brightness attribute referenced when I change brightness as follows:

{
    "event_type": "state_changed",
    "data": {
        "entity_id": "light.livingroomlight",
        "old_state": {
            "entity_id": "light.livingroomlight",
            "state": "on",
            "attributes": {
                "brightness": 124,
                "friendly_name": "LivingRoomLight",
                "supported_features": 1
            },
            "last_changed": "2021-03-26T10:35:07.289108+00:00",
            "last_updated": "2021-03-26T10:35:07.289108+00:00",
            "context": {
                "id": "a8d519de8a5ed2f1a78a9e65583e73e1",
                "parent_id": null,
                "user_id": "211c021e16b24b9ba9839da7be6871a4"
            }
        },
        "new_state": {
            "entity_id": "light.livingroomlight",
            "state": "on",
            "attributes": {
                "brightness": 170,
                "friendly_name": "LivingRoomLight",
                "supported_features": 1
            },
            "last_changed": "2021-03-26T10:35:07.289108+00:00",
            "last_updated": "2021-03-26T10:35:09.459774+00:00",
            "context": {
                "id": "c1477f46363feeb02e5d1c612fc2fa9f",
                "parent_id": null,
                "user_id": "211c021e16b24b9ba9839da7be6871a4"
            }
        }
    },
    "origin": "LOCAL",
    "time_fired": "2021-03-26T10:35:09.459774+00:00",
    "context": {
        "id": "c1477f46363feeb02e5d1c612fc2fa9f",
        "parent_id": null,
        "user_id": "211c021e16b24b9ba9839da7be6871a4"
    }
}

Checking the attributes via Developer Tools -> Templates I see the following:
{{ states.light.livingroomlight.attributes }}

result:
{'friendly_name': 'LivingRoomLight', 'supported_features': 1}

Does anybody know how I can build an automation to trigger based on the brightness change?