There were other things found that a PPI wouldn't reveal that make me cringe as well. So the only time I've actually seen a front bump stop on an air suspension was doing research. This video you can see the orange rubber bumpstop:


https://youtu.be/gbd_EUJojyQ?t=9


On other cars these prevent bottoming out. I don't have my new parts yet for the CV/stops but I'll post pictures of what I find when I do.