forgive me if i'm wrong, but i couldn't help but feel like the documentation for upgrading addons from 3 to 4 was extremely scarce and scattered. i pieced together several documents from MDC, the developer forum, and the Mozilla blog, and still couldn't get a full view of the changes that affected my addon.

revisiting the submission process itself is welcome and seemingly necessary; but i'd be willing to deal with an inefficient submission process if the upgrade was well documented.