I cant get any kind of antialiasing to Shading Normal texture.
For an example Tangent-Space Normal works just fine and Surface Unlit Base Color.
Increasing Baking Samples or Pixel Samples seem to have no effect to it.

I assume you're the one who submitted the question ticket? I already responded to the ticket, but for anyone who might be curious:

You can assign different pixel filters by creating explicit image plane:
Instead of using the quickplane checkbox for “N”, add “Extra Image Plane”, select “N” as vex variable, and change the pixel filter type to “Gaussian 2x2”.