Visualize(Display) the beginning and the end of a title

[fbt78]

As it is possible to parametrize the beginning and the end of a title. It would be practical to visualize(display) all of the title on the progress bar and the wave form and to put the parts not read in another color or hatched.
What do you think about it?

[fbt78]

On the same item, when the duration of reading is modified, it would be useful to display duration in bold or in color in various lists.