I see what you are getting at Sami.. If you select material outside in you edge bend parameters you get this.
If you select bend outside you get this.
If you do a bend material inside you get this.
Therefore it looks like you would be better off with the first option. If you are trying to do a up to vertex on your edge flange with bend outside or inside you are going to get undesirable results I would imagine. Then you would have to do the math and do a blind.
The edge flange sketch is going to begin at the edge of the base and you can't change that.