Yes, HD audio works fine, but multichannel AAC has issues, as it does on U22 android
Interesting!
I have a U9-H but wanted an S922S box so bought an Odroid N2 around February because the U22 was not out.
I had the same thing on that box - everything seemed to work well EXCEPT AAC multi-channel. AAC stereo was OK and I could upmix that to psuedo surround using Kodi setup. I don't have much of that AAC encode (older) material anymore and the few media I valued the AAC multichannel audio stream was converted to AC3 using makemkv.
I have also found one must set the source mode to PCM (channels are RAW on ^o display) to enable the most audio formats on the pass through.