Let's be honest, 5.1 LPCM really should be supported.
It's a mandatory lossless surround codec - actually, it is the ONLY mandatory lossless surround codec.
(Dolby True HD is mandatory for stereo only, and DTS-HD MAS is not mandatory at all)
Currently there is no way at all to use lossless audio in 5.1 in Encore, and this is a dreadful oversight as audio is half of the program.
Bad audio will ruin even the best film, but on the other hand good audio will save a dog of a film.
Encore needs lossless surround support.