(Feature request) default subtitle and audio SG Video

Hi all,

Let me first explain the problem, as there may be a solution for this already.
We are creating a custom audio and subtitle selection overlay for our video's. We encountered the following:
According to the docs (which seems to be right as we tested this) there is a "audioTrack" and "subtitleTrack", but by default they are set to an empty string. We hoped that if a hls stream had default subtitle setting the 'subtitleTrack' would be adjusted to this, but unfortunately this is not the case. 
For the custom selection screen we want to put an indicator before the current playing audio and subtitle track, but as these aren't set by the Videoplayer upon start we can't look this is up anywhere. 
The default Roku popup for selecting an audio and/or subtitle does show the current audio or subtitle, so somehow it can be done.

Can anyone help us out with this?
Or should this be a feature request to let the Videoplayer set the "audioTrack" and "subtitleTrack" upon playing for the first time?

Thanks!