“However, you need to specify ONE input and ONE output. So once you specify your digital source you can't specify an analog input at the same time. And once you specify a digital output you can't have an analog output at the same time.”
Except, you can specify XLR+RCA for your analog output, and use them both simultaneously. I do this in order to connect my powered subwoofer. However, I recognize that this doesn’t help the OP with what he’s trying to accomplish.