There's two new flags accepted by Help::ShowQuickHelp:
QUICKHELP_FORCE_REPOSITION forces the implementation to position the
quick help window according to the current mouse position. Without
this flag, repeated calls to ShowQuickHelp will re-position the window
only if the actual help text changes, which is undesired in cases
where different elements in the UI by chance have the same quick help
QUICKHELP_NO_DELAY specifies that the quick help window should appear
immediately, instead of using the built-in delay used normally.