[scottwick]

What happens if the 2nd signal (after the 200ms delay) is never received? Would keeping the relay closed like that cause any issues?

I wonder if a more "robust" way to handle this would be a custom microcontroller on the receiving end that receives a single Zigbee signal and implements the 200ms delay internally.

[AdamJacobMuller]

It's possible it just melts the relay, possible there is logic to notice and open it, or possible just nothing happens.

There are other products I've used (https://www.amazon.com/MultiRelay-ZEN16-Sprinklers-Fireplace...) which don't have that issue because they handle the pulse logic internally, you set a z-wave option which says "pulse output 1 for 200ms" and then you call a trigger which says "pulse output 1" vs "output 1 on, wait 200ms, output 1 off"

Using that for some years on my garage door opener to make my "smart" garage door smart without paying them $20/month or whatever the stupid fee was.