My intuitive first repose is to build a separate Family for the power supply with the following Values.

System Type= Power - Unbalanced
Load Classification= Lighting
Power State Factor= Lagging

Thus, LED Light Families would not utilize a Connector. Using this method, it would be up to the User to determine the maximum number of Lights per power supply.

Any suggestions on how to improve this would be much appreciated. Would it be helpful if Autodesk adds an LED Value option for their Low Voltage Connectors?