The factory mounted the step fully below the body with a foam strip (F2TZ16536B) between them to protect the paint & prevent noise. The front end is straight & flat under the fender. The Bronco back end curls up slightly into the wheel arch. F-series back ends are flat and curl around under the back of the cab with an integral steel tab.
Note the extra body line at the bottom of the door indicating this is a revised door with a side impact beam.

This would probably be a good addition to the steps, if you can still find a set:

If not, the universal set is reasonably good: