Ensure that when the selection or focus changes, it is in a viewport after the change. 10.5 Avoid default input configurations that interfere with operating system conventions. 4.13 Allow the user to start, stop, pause, fast forward, and rewind audio. In particular, follow conventions for user interface design, default keyboard configuration, product installation, and documentation. 6.2 Conform to W3C specifications when they are appropriate for a task.
Consistency is less important than accessibility and adoption of operating system conventions.
10.8 Allow the user to configure the graphical arrangement of user interface controls. 8.7 Allow the user to configure what information about links to present. 9.4 Allow the user to configure notification preferences for common types of content and viewport changes.