There is another way to protect the notes by changing how they are displayed: bigger number in red are much easier to spot.
To change how end or footnotes style:
- go to home tab
- clik on the little arrow bellow the style frame to popup the "style" widget
- click on the little "manage tab" button on the bottom
- in edit tab: "sort by alphabetical" and find the "footnotes references"
- then customized its style to make it... unforgettable
Thanks to that video tuto (4th video)