Well, I remember that this is a big "no no", but Primm has some totally unusable Navmesh that makes NPCs very confused.

The original game tried to fix this by dropping a huge collision box ( ball ) on the Primm side of the bridge.... watching McGee spaz out on it is really wild.

I'm going to delete these triangles. Why? Because deleting them is only 1 NavMesh entry in my data, while reworking the area results in multiple entries ( 4 or 5 ).

What are the possible issues with deleting them again? ( remember, no one can ever walk in that area anyway )

i think you can delete them in geck, but you have to clean them up in fnvedit.

deleted navmeshes will crash your game among other things.

Idk how bad it is in New Vegas, but in skyrim it was a big deal. But i remember fixing all of the deleted navmeshes in TESVEdit, so there's a way to do it, even if you do delete them.