Or sometimes there's some fine print in the data sheet that says:

"1. Additional processing (MPMA, MPMB, VPM, PPM) post any of the HD audio decoders may be limited."

Which could mean:

"What you want to do won't work." I'm not saying this is the case because I'm no expert on the Cirrus chip. But statements like that lead me to believe not all permutations of functions are available.