Hi @Tom_P,
When you add a Brep to the document, two things happen:
1.) If kink splitting is enabled (which it is unless it is being overridden temporarily by a plug-in), then BrepFaceList.SplitKinkyFaces() is called, which splits any faces with creases into G1 pieces.
2.) If the Brep’s solid orientation is inward, then it is flipped using Brep.Flip().
– Dale