I am not sure if this is the correct place to post this, but here it goes.

I am working on making a sheet metal box and noticed that the corner condition changes when using the Flatten feature, which then translates into the DXF. 

I have attached a sample that shows the condition I am seeing. If the Flatten feature which unsuppresses the flat pattern is used then the flat part has 90 degree corners where the flanges meet. However, if the feature tree is rolled back to the Unfold feature, the corners have a V shaped corner relief which is also visible in the formed part.

I am wanting to understand why the two features that perform essentially the same function have different results. I have seen this in the past and have made the necessary modifications to the flat pattern, but I want to understand why it is doing this.