Im trying to think of all the equipment on my router that is not opto isolated that i have connected directly to my UC4400ETH. The servos are, as I recall the vfd is, so I believe the only thing that leaves is three sensors and a DAC. And I think I remember reading in the uc400 eth manual that's the inputs can sink a maximum of 20 milliamps? And I was careful to make sure that the power converter for the switches and the DAC all share a common ground with the uc400 eth. My point is, I didn't use a breakout board. The breakout board I used was simply an expansion of the connections on the uc400 eth. I could be wrong, but I don't think that a breakout board is absolutely necessary. At least mine's working fine without it right now.