The base flange feature is not used with the lofted bend feature.
Solidworks sheet metal lofted bends.
To view this part in flatten form click sheetmetal flatten.
Lofted bends in sheet metal parts use two open profile sketches that are connected by a loft.
The bent manufacturing method creates real physical bends rather than formed geometry and approximated bend lines in a flat pattern.
Look at part tree.
Set bend radius to 0 03in and k factor 0 5 and ok.
To find out more about lofted bends you need to dig a little deeper into help and do a search for bent lofted bends unfortunately at this current time i am only able to find information about formed lofted bends in the solidworks training manual for sheet metal.
Under manufacturing method select bent.
Click sheetmetal insert bends click flat face as reference when it flatten.