Managed to flash the firmware on my first Sonoff RF switch.
Was definitely an interesting exercise and I can see why most people wouldn't go as far.
Very happy with the outcome. That said, the only work was to do some soldering, connect to my FTDI usb-ser device, and figure out how to flash the firmware. The rest was super easy, since I already have a working MQTT server and Openhab set up for my DSC alarm. Now I can control it through both the RF remote and through Openhab, and if I really want, manually send MQTT messages or use the web interface on the switch.