Rapid detection of BLE device entering range

I have the GL.iNet GL-S10 bluetooth proxy running ESPHome and Bluetooth BLE iBeacon (BC-U1-MultiBeacon) – USB powered from BlueCharms.

I want to trigger an action as soon as possible when the BLE Beacon device is detected by either the built-in Bluetooth or GL-S10 proxy in Home Assistant.

What is best way to do this?

As dumb as possible would be ideal (I’ve tried BLE triangulation and iBeacon add ons, but they seem to have a lot of false positives and negatives). Maybe detect by Mac address somehow?

Thanks!!!