The profile properties such as geometry, feature definition etc. can be modified. The below code snippet shows how this can be achieved.

Example

internal void ChangeProfileProperties(Profile profile)
        {
            //Get active connection object
            Bentley.CifNET.SDK.Edit.ConsensusConnectionEdit con = ConsensusConnectionEdit.GetActive();
            //To save changes to dgn
            con.StartTransientMode();

            //set new feature definition to profile
            string featureDef = "Alignment\\Geom_Baseline_Driveway";
            profile.SetFeatureDefinition(featureDef);

            //Set new geometry to profile 
            Bentley.GeometryNET.DPoint3d[] points = { new DPoint3d(100, 100), new DPoint3d(600, 110), new DPoint3d(1000, 105) };
            Bentley.CifNET.LinearGeometry.ProfileElement element = ProfileElement.Create1(450.0, 750.0, points);
            profile.AssignGeometry(element);

            //To save changes to dgn
            con.PersistTransients();
        }