JBJ2
Is PIXEL 3 show all icons including Bluetooth, alarm, etc when hide notch? If No, it is not possible ...

I think yes. It does show all the icons when hide notch option is implemented in Pixel 3 ( link : https://youtu.be/eAPL6Y6qB6Y ). I couldn't even suggest anyone to wait for updates as Poco developers are busy in playing games.