ESP’s are on my list as is esphome, but for these door sensors I wanted ethernet connectivity and not wifi for absolute speed and reliability as well as POE as all my switching is on a UPS that is generator backed so this keeps the door sensors up in a power failure.
Also the alarm panel terminated in a cinder block utility room in the basement and wifi coverage was challenging but ethernet plentiful as also where all the structured house wiring terminated.
I’ve been watching for ESP’s with ethernet and POE as a long list of things to build with those!