Admittedly I don't know much if anything about electronics and on the couple installs I have done I have always just copied what someone else has done. On my work bench right now I have two ScaleTrains SD40-2s that I am hardwiring an LM3-S into. I am using the factory LED light boards and also installing two ditchlights with two 0402 SMD LEDs. On my previous LED installs I used the supplied resistors, one on each LED lead. Recently it was suggested to instead install the resistors on the blue common wire. How is this different than being on each LED wire, it seems easier?