Autodesk Advance Steel is an AutoCAD vertical application made for steel fabrication. It is great at creating joints between members and a lot more besides.
In general, the commands work very well, but I did pick up a limitation on one of the commands when I was recently working in an exercise file from a textbook.
When a plate is being modified using the Polygon Contour command, one can put in a negative offset, but then the fillet/radius is not possible.
In a case like this where we are unable to achieve the task with the given tool, we then must do a bit of construction of lines before we can complete the task. We sketch the outline and then we are indeed able to complete the corners with radii.
If you need help to use AutoCAD Advance Steel in your practice, please contact Micrographics so we may be of assistance.