I ported the Xiaomi MiJia Honeywell Smoke Detector driver, and can tell you from all my research there is no way to trigger the alarm by sending commands from a hub.
The only thing that can be done is to send a "test" command that makes the smoke detector beep once, and since the beep is not loud at all, it's not very useful.
Please note that I am working on a new driver for the Xiaomi MiJia Honeywell Gas Detector and based on this experience will be greatly improving the driver for the Smoke Detector.
Stay tuned to this thread for an announcement when I release that new Smoke Detector driver:
