Is it then futile to try to achieve the goal of true Dolby Digital passthrough from a media player? If it is possible, kindly suggest a solution.
Believe it or not... the (lowly) latest FireTV 4K Stick running Android Kodi is capable of DV playback AND HD Audio passthru.
I'm not a big fan of low power android devices, but one can call it a better "solution" than any PC could ever dream to be.