There are a few places that are quite interesting and that could be expanded in the future by making aditional deeper caves under them that would require us to have later upgrades for example tadpole depth mk2. And add some story significance where we scan something and learn more about the bloom and things, there could even be story bits told by how the terrain looks. Some of the places that come to mind are: spider dome, cave where zip died, wreck that was moved over the cavr with bloom infection, starting are trench, cave under the necrolei hill.
These places are really interesting but I feel like they couls be expanded both in depth and interesting info that we can get only by visiting them later with better equipment.