There's a shadow that the neat bar creates when using shaders and will not disappear unless you enter F1 mode. Can you make the bar transparent or something as it doesn't make much sense there being a shadow.

whether there's a shadow or not is up to the shader engine, not Neat.

It shows up with every shader that I use. BSL, Both versions of Complementary, and Sildurs. It's a lightly transparent box so I thought it would work like normal multiplayer nametags and not show up with shaders. The Neat tag acts like a full part of the player model making causing a shadow.

That's because the name tag is rendered completely different

If this is still relevant in newer versions of the mod (1.20 onwards), please open a new issue