Is there a way to program the player to read the hi-rez stereo layer of SACD rather than down mix the MC?
You are reading the manual out of context.
In General...
SACD discs can have both a stereo layer and a multichannel layer on the same disc and you choose which to play.
Most stereo players default to playing the stereo layer or can be set up to do so.
But, if the multichannel layer of the disc is selected, a stereo (2 channel) SACD player will down mix the multichannel program to stereo, if the player is capable of reading and playing the multichannel layer.