Hello
It seems there isn't a straightforward method to prevent a specific BLE device from being displayed on the Windows OS Bluetooth device addition screen.
However, you can control the visibility of your BLE device by implementing a pairing or bonding mechanism that requires a user to input a PIN or use a specific button sequence to pair the device. This way, even if the device is visible, it won't connect to other devices without the correct authentication.
Additionally, you could consider implementing a 'whitelist' within your BLE device's firmware, where only devices with certain addresses are allowed to discover and pair with it. This is a more complex solution and would require careful management of the whitelist.