My guess is, like many accessibility tools, it will vary by person! The Storyteller apps don't actually support this multi-level granularity demostrated in the demo here — until this iteration of the alignment algorithm, the timing wasn't good enough for word-level highlighting. So currently we only do sentence-level highlighting.

When we do roll out multi-level granularity, it will indeed be something that you can configure yourself, including how each level is indicated (e.g., you might want to set a background color on the sentence and underling the word) and whether a each level is indicated at all!

The "spread out" highlighting is a really neat idea, I don't think I've heard that suggestion before!