The Swept Flange tool is similar to the Sweep tool; you need a profile and path to create the flange. To create a swept flange, you need an open profile sketch as the profile, and a sketch or a series of existing sheet metal edges as the path.
Any chamfers or fillets on the bend region of the swept flange do not appear in the flat pattern.
For flat patterns, the software calculates a linear calculation. Compression and stretching of the material are not taken into account.