Maximum Image Resolution image field setting ignored

If I add an Image field to a content type and configure it with a maximum image resolution (e.g. 1500 x 1500 pixels) then the default Drupal image widget will resize larger photos to 1500 pixels maximum.

If I change the widget on the Form Display tab so that it uses Plupload Widget instead of the default, then I can upload a much larger file (as long as it is below the PHP upload size limit) and it will no longer be resized - it seems to bypass the Drupal maximum image resolution setting.