With arrival of DSM 7, there's been changes with Audio Station,
as a result, GAPLESS PLAYBACK finally works!
on the other hand .CUE sheet support is broken (and wasn't present in DSM 6/6.2):
if an album is one .FLAC file with tracks defined by .CUE (text) file, tracks are cut off randomly, elapsed duration is displayed wrong, playhead disappears and gets stuck on right edge of Audio Station window
Synology knows about the issue, I even went through quite detailed support ticket thread, yet after almost 5 months the issue hasn't been fixed yet!
as a result, GAPLESS PLAYBACK finally works!
on the other hand .CUE sheet support is broken (and wasn't present in DSM 6/6.2):
if an album is one .FLAC file with tracks defined by .CUE (text) file, tracks are cut off randomly, elapsed duration is displayed wrong, playhead disappears and gets stuck on right edge of Audio Station window
Synology knows about the issue, I even went through quite detailed support ticket thread, yet after almost 5 months the issue hasn't been fixed yet!