The baked GI node in the shader graph is mainly designed to access the baked lightmaps, and it’s a great node. You can also use this node to access the ambient lighting information of the scene, while the ambient node provides individual access to the sky, ground, and equator colors (and if you want the actual ambient light, you need to interpolate manually in your shader between these three), The Baked GI node gives you the final calculated value of the ambient light for a non-static object.
The problem is that looks like Unity “Adds” the ambient lighting value to other lighting information when it comes to calculating the direct lighting and “Multiplies” the value of the baked lightmaps with other lighting values while calculating the indirect lighting. Imagine that you need to make a shader for your game environment and you want to implement some kind of custom lighting, well because in one scenario you need to multiply and in another one, you need to add the output of this node while blending it with other values, you need to make two shaders. (Or you need to calculate a three-way lerp between values of the ambient node.) I think although it might be a minor problem, it would be good if you guys think on the topic, maybe even think of a way to find out if the object is static or not when using the shader.