alain pierrot on time chunks in books

Alain Pierrot gave us permission to repost this:

Martyn Daniel’s remark about Ether Books’ move into the digital short story, which can be “read as installments” (thanks to Virginie Clayssen for the link) rang a bell for me about the way many kinds of readings compete for chunks of my attention.
Can I read the next chapter of this essay, study or novel before I’m called to board the plane, before my train comes to the station, or should I pick a shorter magazine article or a short story from Ether Books, etc.?
On a more professional field, can I spare the time to read the full version of the report, or should I restrain to the executive summary, plus the most relevant divisions of the report before the meeting?  
Or in academic situations, what amount of reading time should I plan to spend on the textbook, on the recommended readings and extra relevant titles before I sit term/final examinations?
Cross this with the last remarks in the excellent post from Information Architects, about their work on Average Reading Time (ART): 

Imagine, when you read a book, it doesn’t show you how many pages are left or how many words you have read, but how far into the text you are time wise and how much reading time is still ahead of you. Imagine that, when you write a text it doesn’t count words but the right column tells you:

  1. how much time you spent to read your text until the cursor position (top number)
  2. the total reading time (bottom number)

iPad-time-counter-ART.jpg
And they prepare to manage calibration, which should allow to match individual skills, reading situations, with different texts – I don’t read Joyce’s Ulysses at the same rate as the last issue of Wired !
Wouldn’t it be a good idea to leverage all the occasions where digital texts are chunked in relevant spans to store their ART into metadata, made available to apps that would sort timewise what I’m proposed to read? Social media and relevant storage solutions might host measured ARTs at convenience.
XML structured editing affords many solutions for identifying the relevant sections of texts, and storing their length, timewise. I would love to see the feature embedded into a next version of ePub, or at least recommended as best practice.
Would that make sense for Google Books, Amazon, iBooks, publishers, librarians?