The Bounding Sphere in the mentioned *.NIF and BSTriShape/NiTriShapeData block has a Radius of 0.0.
The model or parts of it might be invisible in the game. If the model can be seen in the game and seems to work as expected, nothing needs to be done.
The NIF can either be updated with Cathedral Asset Optimizer for either block type or with NifSkope for BSTriShapes only - right click, Mesh, Update Bounds.
An already generated LOD patch should continue to work as is.