Attach the tech specs of the main/sub controller for your reference
What means the "port",let you know that each sub controller has 8 signal transmission port
Regarding to the when to use the signal amplifier,when the transmission distance is too far so you can consider to use the signal amplifier, as the wall washer signal connect to 150m so it needs using to stable signal,D33 connected only to 30m so do not needs it