Automatically fit texture to the bounding box of mesh?

[speltrong]

Is there a way to automatically fit a texture to the bounding box of the mesh?
I'd like to create a generic gradient material projected in XYZ to UVW that I can apply to any mesh regardless of size and UVs, and then just need to adjust the knots themselves rather than the scale and position of the texture node as well. File attached for reference.

Is this possible?

Thanks!

-s