Yeah. It's easy to make the DSP switch to the CD_2 I2S input instead of CD_1. You just need to modify the empeg mixer code to allow it to select the other input. The register definitions to select the I2S inputs is on page 63 of the DSP docs.

I'm not too sure how to make the empeg connect CD_2 to the tuner lines though which is main problem. Anybody from empeg know?