I tried getting the Nexia NX1000 to work with the Remotec device handler, but I never could get it to work. I have developed a specific device handler for the Nexia NX1000 based on work done by a coupe of others for SmartThings. It works as a button controller.
A few notes about its use:
Define the button labels you want then click the Configure button. The NX1000 will not begin to update until it wakes up. It usually wakes up on its own about every 70 minutes. If you're impatient like me, press one of the page buttons (the three buttons below the screen. It will take about 30-40 seconds for all the labels to update. Wait for it. You'll be glad you did.
Here is the link to the DH.