The 500K one helps with CCR/CCB. If you run your LOR via Comm ports then you are limited to
http://www1.lightorama.com/Documents/DMX-DOC.pdf
But if you run under DMX , you can have multiple identical ID's. For example Off my Pixlite's I run a crossover connector off the 485 ports, map that output as Universe X, make my LOR boxes ID 1, 2, 3, and channels (hardwired) 1-48. So each output can have an ID01, 2, 3.