Reader keyboard shortcuts were attached to the list of entries rather than the page, so j, k, o, v and m did nothing until you clicked an entry first - while the shortcut panel listed them as though they worked. They now respond as soon as the page loads.
The ? key also had two owners: on Reader and Notes it could open the Help drawer instead of the shortcut list. Every surface now shares one shortcut list, generated from the keys that are actually installed, so what the panel shows and what the keyboard does cannot drift apart. ? opens that list wherever a page has one, and the Help drawer everywhere else.