I'd check with Expert Sleepers on that point, actually. I doubt they'd put lightpipe I/O there without being able to send/return ALL of the channels; remember, this is not exactly a "normal" ADAT lightpipe interface, but something that talks to whatever CV interface app is in use. But if you want the smaller footprint, the ES-3/6 combo would also be a good fit...just remember that it hasn't got the USB interface that allows you to directly connect a MIDI controller to it in addition to the normal I/Os, and it also only handles outputs. However, you can expand that arrangement to a massive 64-outs for both gate/trig and CV.
Even so, the cheapest and easiest solution still appears to be to use an outboard DC-coupled audio interface. I use that, and so do others here.