Yes there's a switch between "streaming" input and analog.There is a Bluetooth USB adapter from Dayton that allows you to play music from your phone directly to the DSP. You will probably get a better result using it.
Since this USB adapter also allows you to control the DSP adjusts from your phone, you could also use the RCA (connected to your HU) If you wanted to, plus the USB. Whenever you want to change from one another, just access the adjust tool on the phone and change the input mode from RCA to USB.
**I think it would work, never had experience with a Dayton DSP.