I had the same dilemma. I wanted to “modernize” my old alarm panel and was thinking about just upgrading it to something new. But then I stumbled upon home automation while doing product research. Instead of spending over $1k on something new I spent it on a couple of wall panels and additional z-wave sensors. I’ve been bitten by Home Assistant and am now a rabid member. I already had a VMWare server so I just added the HA appliance and viola! One thing though, you really do need to use the paravirtual SCSI controller and VMXNET3 NIC or you will get console errors that build up until it crashes at random times. Add those two and rock solid. But I digress, back to the alarm dilemma. I saw the Konnected thing and was going to go for it until I saw that it was almost $300 for 16 contacts. After doing a ton more research and going down many different rabbit holes I came across a Kincony product - KC868-A16 - arduino ESP32 16 channel GPIO module – KC868-A16 -. They have mosfet and relay output versions and I saw potential. I bought one for about $32 shipped to my door. At first I was trying to augment my panel, which was going to take a bit of electronic work, but then asked myself, “Why. Why do you need the old alarm?” After a couple of days I realized I did NOT. There is NOTHING that alarm board can do that the new HA installation can’t as long as I have access to my binary sensors. It was a rip and replace using the same cabinet and the Kincony board. Being a noob with esp32 stuff it did take me a little while to figure it all out but since I’m a network engineer it was only a matter of time. 5 months in and I couldn’t have imagined what was possible. I’m so glad I didn’t get another traditional type of alarm system.