It can bitstream output it to a receiver, and that works reasonably reliably in PowerDVD 18 (though if you change playback media from say, DVD to Blu-Ray you typically have to go back into the PowerDVD preferences and re-select bitstream for audio output). PowerDVD cannot downmix or interact with any Atmos or DTS:X content.
My research thus far into UHD disc playback indicates that the only official way to play back UHD discs is via PowerDVD, and the hardware requirements are very narrow due to industry requirements for DRM:
