Observed in Firefox extension. If an edit window is opened, it will block a configured timeout from triggering an automatic lock or logout. The danger is when the edit window is unnoticed by being under another window or minimized.
Ideally, an edit window should require active user interaction to block timeout. Pending changes should be cached or discarded.
Alternatively, an idle edit window should be more conspicuous. Display a notification or popping to front on idle timeout.