Interpolation of Vertex Data

I've been searching around for information on this with no success. Unlike other threads, I'm not trying to stop interpolation. However, what I am trying to get - is consistent interpolation.

I've noticed that, when assigning the same data, the UV and UV1, the tangents, and the color channel, the values are all interpolated differently when interpreted in the surface shader.

Here I provide data to the mesh; I deliberately have given them the same info for testing.
Interpolation of Vertex Data