the boundaries you loaded are fine. the simplification only occurs when iNat delivers your place boundaries as vectors. probably you see the extreme simplification here because you’ve created a single place that contains 3 distant locations. (personally, i would have created each of the campuses as their own place in the system.) but the simplification of the polygon vector does not affect the ability to filter for observations in your defined boundaries.
you can see a better representation of the actual boundaries loaded in the system if you request the place polygons as map tiles. here’s what i see in my custom map (when i enable the iNat Place layer):
