Thanks for your feedback on the doc. I have revamped it according to all of the comments. The major changes I have made are:
* The problem description should be more general and accurate now.
* I added more background information, such as details about Reshuffle, so I should be easier to understand now.
* I made it clear what is the scope of my current project and what could be left to future work.
* It now reflects the current progress of my work, and discusses how it should work with the portable pipeline representation (WIP)
Also, I forgot to mention last time that this doc may be interesting to those of you interested in Reshuffle, because Reshuffle is used as a current workaround for the problem described in the doc.
More comments are always welcome.