It's only a 2 function decoder. The 6-pin platform doesn't allow access to any more than that. I suppose they could have made pads available on the circuit board, but then you'd lose the easy plug n play feature.
The Digitrax decoder has the same limitations for the same reasons.
I've got 3 ES44DC for NS waiting for me to decide if I go with the simple plug in decoder or go all out and add flashing ditch lights. Probably via a TCS M4 (it's the same size as the EUN651 minus the pins) or a Digitrax DZ143 (which is slightly larger) or a DZ163 (which is a fair amount larger)