It's unclear whether the blocklists defined in the main Web Bluetooth spec are intended to apply to the Web Bluetooth Scanning specification.
The manufacturer data blocklist includes an entry to block advertisements that match the iBeacon format, but the Web Bluetooth Scanning specification includes an example that suggests it's possible to discover iBeacons with this API:
https://webbluetoothcg.github.io/web-bluetooth/scanning.html#introduction-examples
Can you clarify whether scanning for iBeacons with requestLEScan is intended to be blocklisted?