You could try the new preview version. Details on how to access it are here: Try out our new Vizio SmartCast preview
This version will eventually replace the current app. Testing for this version found that FLAC playback was fairly unstable for Vizio TVs (i.e. attempting to direct play it caused bad things to happen 
). Currently this preview version will always transcode FLAC, but we have an issue filed to see if we can improve this by figuring out if there are some scenarios where direct play is safe.
