With the Display value flow on Tracks enabled, Tracks will draw their state of value processing in addition to the interpolation curves. This could be handy when you use Keyframes without interpolation, or when you zoom into a Track portion that does not display any Keyframes actually, but you need to know the position of the last Keyframe.
Displaying the value can be enabled from the Project menu, and of course you can set its global behaviour state in the Preferences.
