Model Normal & Tangent Settings.

When I export my own Normal / Tangent information or use unitys "Calculate" setting for normals, it creates inverted vertecies on all of my dense mesh areas. Does unity have some sort of a vert limit within an amount of space?

Is there a way to manually update the normals to acompany blendshapes or am i stuck using standard-no-update normals even tho the mesh has changed simply because Unitys calculate setting destroys my mesh?