To be honest, if you can afford it consider replacing the whole alarm with a Bosch Solution 2000 or 3000 and Bosch B426 IP module. You can reuse your existing wiring and probably the PIR sensors, maybe even the siren, you will need new control pads though.
When I was looking just a couple of years ago and when Konnect first came out alarm systems didn't natively work with things like Home Assistant, but the Bosch does and others probably do too now.

I recently replaced an old Paradox alarm with a kit from these guys for $649.
https://www.alarmwarehouse.co.nz/Products/?category=167&product=926/Bosch-Solution-2000-Kit-with-ICON-Keypad-Sirens-APP-Module-and-2-Std-Detectors

It hooked straight into Home Assistant natively with this custom integration and works great.
https://github.com/mag1024/bosch-alarm-homeassistant

Was a couple of days work (because I didn't know what I was doing) but it's a much better outcome.

Even if you don't go down the Home Assistant integration path, the Bosch mobile apps etc are free compared to Arrowhead. You can download the firmware updates without being part of a special Arrowhead installers club etc.
Just a much more open and usable product.