Honeywell Vista Alarm and AC setback

I have attempted to search the site for ideas for AC set back, haven’t seen much. I had a system based on the alarm in the away mode that worked reliably, gave it up with a new alarm (Honeywell Vista-20P) and a new Thermostat (Honeywell WiFi Visionpro 8000).

I am able to get a relay contact out of the alarm when the alarm is in the “away” mode, and thought I could send a door/window sensor to notify ST hub. I realize this will appear way too complicated to some, and I’m open to other ideas. This is the most automatic way for multiple users, I think, that doesn’t require cell phone presence, or pushing a button, or motions detection. If the alarm is in the AWAY mode, pretty good indication the home is empty.

Unfortunately, the alarm does not give me a simple relay on / relay off for the AWAY indication, I have basically "close for 2 seconds, Continuously pulse on / off, toggle relay, or relay closed for a time I can determine. What’s weirder still is whatever action is triggered doesn’t ever stop, as far as I can tell, so hard to use it to put the thermostat back to normal when the alarm is turned off.

This doesn’t even get to the problem of can I make the ST hub set back the thermostat. I am new to ST, have only done the most basic of automations.

Any direction or guideance appreciated.