Questions about Xiaomi Security Kit

ello all! I have few questions about the Xiaomi Home Security Kit.

So, if you go to Gateway > Auto > Alert > Trigger Device you can select if you want to activate the alarm with any sensor from the list, right? Also, we can set SCENES to trigger alarms, for example, (Sensor1 AND/OR Sensor2) = AlarmON, correct?

Problem is, even if system is disarmed, the scenes will trigger the alarm sound. Right now my alarm is working with scenes OFF, only trigger devices active. Is there a way to deactivate the “Trigger devices” and use the Scenes instead?

I’ve tried to disable the trigger devices, then set some scenes active, but they are still being activaded with alarm disarmed and with a different sound and duration from the one I set on Gateway > Auto > Alert > More Settings

Also, I would like some other noiser Siren, is it possible to connect it to the system? Any recommendation?

Thank you all!