I just encountered this and thought I would share a few things that would have been nice to find in documentation :/. I have the second generation (non pro) alarm and add-on boards.
Both Zone 5 and 6 on both boards momentarily go high during reboot - meaning if you are driving a siren via relay from them, power outages/reconfiguration is going to reduce the WAF somewhat! I was already using Z1-3 on both boards, but Z4 at least on the add-on board did not experience this (it stays low during reboot, and hence the relay doesn't trigger and I don't need to get a divorce)
Also, when trying to negate the above, I tried to invert the switching logic using the (supplied with kit) 5v relay board. It has H/L jumpers for each input, so I tried using inverted logic on the siren output (in Home Assistant, configuring the output as LOW when active) with a L switched input on the relay board. Unfortunately, this wont work, because the relay board is 5V, and the non low output of the zone pin is 3.3V, the ~1.7V difference between the 5v ref and 3.3v output of the zone is enough to hold the relay on. This issue is eluded to at https://docs.konnected.io/security-alarm-system/wiring/siren/ 'For this application, keep the jumper setting on for high level trigger (it’s shipped in this configuration).', but no explanation of why. Without a 3.3v supply on these boards, there may not be a way to have a low switched relay.
Both of these things should be detailed in documentation, and although I absolutely love the Konnected devices, my one mild frustration has been the lack of detailed basic documentation about the board outputs. (Lots of guides about how to do things, but no actual detailed pin out description of the boards themselves online.). Voltages. Current limits. Behaviour in different configured states. The fact that the Alarm is switched ground. etc.
Hope this helps someone else avoid the several hours it took me to figure this.