[Feature Request] Preserve metadata when transcoding audio files

Currently Plex strips all existing metadata when transcoding audio files.

Please change it (or make it optional) to preserve existing metadata when transcoding audio files.

The reason for this request is that I like to use a different player when playing back the music on my client devices, but use Plex for casting. And using Plex to sync music to my mobile allows me to very conveniently add a couple of albums while at work for the trip home. So I very much would like to be able to sync and cast using Plex.

However the built-in Plex player does not support ReplayGain nor seamless transitions. As such I prefer using another player when playing music.

Currently I’ve resolved this by always selecting the max quality when syncing, which prevents transcoding. However this eats a lot of storage space on my mobile devices since the originals are in FLAC format, and so I would prefer being able to use transcoded files.

However without the metadata, my external music player cannot sensibly identify the music, and just lists a bunch of track1.mp3 files.

Note that I’m in particular interested in the ReplayGain metadata in the existing files, so simply injecting the metadata from the Plex library, but not preserve the existing metadata, is not ideal.