Wouldn’t say this, a surface object in Rhino owns a render mesh for visualisation, but it also contains a mathematical description. So if you modify a surface object in Rhino, you also modify the formula behind. In Cinema4d you create a loft, you can also change that loft, but you cant do more with a loft except lofting. Simply because the loft object returns a mesh only, not a surface object with a mesh. This is a tiny but important difference. If you can import iges, why just not exporting the file in iges then? Don’t know, but iges import seems to be a newer feature… anyways