I need to have a sheet metal tube and want drive the seam location with planes. I have found that SW cannot make a revolve when you have a curve on the inner tube, when you select: "up to surface", this is done in normal 3d moddeling and not in sheet metal. I think it's a bug and needs to be resolved by Dassault. In the first picture you can see how it should work, second picture shows the problem.