nevo tech support is wrong or you misunderstood 

any device you add will show up on the nc50 list for port assignment.  you dont need to assign it to anything if you want to be controlled via direct ir though the remote itself.

if a device needs to be assigned to a port and you have not yet done so, the button will show up with an orange triangle.  the only devices that need to be assigned to a port are voltage/video sensors and serial devices.   

that said, i will test this on monday to confirm.