I know that we can copy/pas keyframe as text . This function requires to realize for each 3D path. I wonder if there is any way to export Keyframe of 3D paths to excel file and import excel file to update keyframe of 3D paths.
This is currently not possible, and would suggest creating an idea for this here.
4D Pro does have the ability to convert an imported polyline, including curves, to a 3D path. This may serve your purpose as you can define a more precise path in almost any model authoring tool.