From when I first started using SWX I asked this question and have never gotten a solution. ( I am using SWX 2015 sp5)

We do most of our own machining and only a small portion is on sheet metal (usually aluminum) and we typically use thicknesses on .125 and less.

We also usually want very tight bends and until recently did not have or use a break to do our bends.

In many cases (like the attached part) we would not be able to make the bends tight enough (even with a break) without fracturing the Aluminum on the bend unless we thin the material at the bend line. 

We have been doing this for years and it works well except that SWX will not allow us to bend along an extrusion on the sheet metal (you can make a perpendicular extrusion to the bend line and it will bend, but not parallel to the bend).

I have tried many ways to achieve this with no luck.

We typically will create the part using a sheet metal thickness equal to the kerf thickness and then thicken the areas outside the kerf by adding a boss extrude.

This will achieve the desired final part but once a boss extrude is added to a surface it makes SWX treat this as a solid part and no longer as sheet metal (it suppresses the ability to get the flat pattern).

I have tried to also thicken the part before bending but the boss extrude on the bent edge will not remain attach (only the underlying sheet metal thickness will bend).

I have tried to model this as a solid body part and extrude the unwanted areas - but again this is now a part rather than sheet metal.

I need to show the flat pattern for machining and the bent part for final fabrication.

This has been a major frustration for us for years and I hope someone can suggest a viable solution or work around.