From what I can tell those Octopus III's would have done everything you wanted. You just tap into the 3 conductors of the SPDT control switch for the bi-color LED. Not sure of the polarity without looking through the manual but looking at the Tam Valley control switch that is what they did using a servo Y connector with one end going to the switch and the other to the LEDs. I have 3 of the Octopus III's yet to be installed along with the aligner tool. If the ESU units go on sale before I start my layout I'll likely sell the ones I have and get the ESU's.