Headphones

I have the DX3 Pro+ paired with Kiwi Ears Orchestra Lite and was wondering what the best settings for this DAC/AMP are. I know there are filters to choose from, as well as low/high gain and then the 3 output options on the controller (headphone only, line out only and then the big middle button, headphone + lineout). My confusion lies in that when I only choose the headphone option, the "DAC" text disappears from the screen. Does this mean I am not getting the DAC benefit from the device only the AMP benefit? As you can tell, I am fairly new to this.