[KevinH]

Can't. As the watcher javascript to detect dom changes does not always work. Therefore File changed status is literally determined at close/leave points by comparing pre and post xhtml dumps from the QWebEngineView. It is the only way to accurately detect if changes have been made internally.

And remember PageEdit, as its name suggests, is a single xhtml page editor, not an epub editor. It work on a single file as a time and either saves the changes or does not when you leave that page in any manner.

But adding a "continue editing/don't leave" option is doable for a future release but you will not then be able to navigate away.