- I would recommend the Sonoff Tasmota route as it is well documented and, for use in a critical application like yours, can send regular status messages over MQTT. This is an important aspect, you need to check regularly that everything is working!
2 @Paul-Reed shared a link to an AlliExpress supplier which I am also using. They are cheap and ship reliably too:
3 I am just using an MQTT in node, I was not aware of node-red-contrib-sonoff-tasmota node.
