It is fully reflowable. Try it! That's why I posted the .prc.
The numbering and lettering themselves are actually hard-coded, not generated at view time by an OL element. However, I am assuming that by the time a piece of text gets to the stage of formatting for the Kindle, it's pretty much finalized, and the numbers aren't going to change. So who cares if it's not an OL with on-the-fly numbering?