You really just need one instance of Theengs Gateway
and the Add-on configuration is the only thing you require to be able to enter the Identity MAC address and Irk for you Apple device(s) - as well as the MQTT integration and an MQTT Broker, either also with the Mosquito HA Add-on, or any other MQTT Broker running anywhere on your local network.
Have you got all these?
Then to extend the range to pick up your Apple device(s). throughout your whole home, one or more ESP32s with the esp32dev-ble-mqtt-undecoded binary of OpenMQTTGateway. similar as described in this thread, even with a different controller system and the Add-on for that controller.
Then once the Identity MAC and Irk has been correctly entered into the Add-on configuration GUI, and Discovery is switched on for a few minutes, the Apple devices will show up auto-discovered within the MQTT Integration from where they can be added to any dashboard.