Still AAC 5.1 audio is output as 2 channel stereo only.
Is there anything more i have to do?
This is going off topic.
Never gave AAC 5.1 a go myself. Always use FLAC 5.1 for HQ audio or SACD with straight DSD output, this next to BD pure audio which works fine. My SQ audio is still all MP3.
I think you should report it formally as a feature request. Did not read anywhere that it was supported , only if it was then it is something missing and a bug. There are several flavors of AAC encapsulations so you will need to be precise both when asking and testing.
SACD support with DSD RAW output is regarded a bug as it was clearly advertised with support for it.