Just in case anyone was wondering if it is possible, you can connect this to HomeKit if you run it through another bridge. I have my switch connected to SmartThings and SmartThings connected to HomeBridge to expose it in HomeKit. Works great.
I've gotten the switch connected through SmartThings, but would like to control it through Alexa (via SmartThings). I have lots of other things connected this way, but I don't see the switch added when I try to rediscover devices with Alexa. Is there something that needs to be done to enable this? FYI, I can control this fine in SmartThings and have even connected it to HomeKit through homebridge-smartthings. I have the non-Zigbee version of an Echo, but this should be fine to control anything managed by SmartThings.