@GoSycamores Samsung SmartThings have a Zigbee chip so you should be able to add it to the Deco M9 Plus which has the Zigbee antenna.

Here are the Samsung SmartThings devices that have been tested so far:

F-CEN-APP1 (Outlet)
F-IRM-US-2 (Motion Sensor)
F-ARR-US-2 (Arrival Sensor)
F-WTR-US-2 (Leakage Sensor)
F-MLT-US-2 (Multiple Sensor)