Can I change how long the Nova stays paused before a track is stopped?

This is controlled in the Soundwall App under Customization - Pause Timer, and can be set to 10, 30 or 60 minutes. The lights on Nova indicate a countdown showing how much time is left before the track is stopped.  When the lights disappear, the current track is stopped.

You can further customize the timing of the Pause Timer at my.soundwall.com - Customization.