I have been searching for a simple and tiny relay switch to use with Smartthings. I believe I have found it. I have been testing the device and created a Wiring Diagram that is more useful than the one supplied by Vision. This product was intended to be used behind non-smart wall switches to allow you to make a dumb-switch smart. This works in Smartthings without a custom device handler as a simple switch.
If you change the device type in the IDE to say a Z-Wave Virtual Momentary Contact Switch then its applications open up tremendously. Also the RELAY on the Vision ZL7431US is isolated unlike the Fibaro switches I have tried. To me having the isolated relay makes this much more useful for other projects. Also because it is much more tiny than say the Linear FS20Z (also an isolated relay) I can hide/stuff the Vision ZL7431US into tighter places.
I have found that if you create a custom Device Handler to mimic the built in Z-Wave Virtual Momentary Contact Switch you then have control via code to change the momentary delay. By default the built in Z-Wave Virtual Momentary Contact Switch has a delay of 2 seconds. I have personally changed this via a custom DH to 1 second (again more useful for things like a garage door, coffee maker with momentary switch, etc.)
I am sharing the Wiring Diagram I created here. Feel free to use it or modify it to help design your own projects. I am also sharing 3 links to where you can purchase your own Vision ZL7431US. I would like to see more people using it so it won’t be discontinued. They are very inexpensive compared to other solutions.
Enjoy!
https://www.thesmartesthouse.com/products/vision-single-relay-module-switch-zl-7431-us
https://www.amazon.com/Vision-Z-Wave-Micro-Switch-1-pack/dp/B01GQX1GFC