OK I understand. Unfortunately we do not have any nodes yet for grading groups or grading objects. So the creation of those would have to be manual. However, you could automate the initial creation of the platform solids and feature lines with Dynamo. After initially creating the feature lines (using the Civil 3D Toolkit package), they would have to be updated manually with any adjustments. Changing the inputs in Dynamo will create feature lines with different names, which will break the grading objects.
Anyway, I hope this gives you a start. For a fully automated solution, it would be possible to skip the feature lines and grading objects altogether and compute the daylighting directly with native Dynamo objects. But that would require a more complicated graph.
CreatePlatformGeometry.dyn (52.0 KB)
Platforms.dwg (600.9 KB)