In the Steel Joint add-on, you can use not only the usual member types of "Beam", "Truss", and so on, but also the member type of "Result Beam", as well as cross-sections from surface elements. You should select a suitable cross-section for the result beam and then define any member openings in the surface model using the member editor.
The "Surface Contact" component in the Steel Joints add-on allows you to take into account a pressure contact between two parallel plates/member plates. Furthermore, you can optionally consider the friction between the surfaces.
The "Stub" component is available to you in the Steel Joints add-on. It allows you to extend a member using a purlin joint with another member (stub) and to connect it to a reference component.
In the Steel Joint add-on, you can arrange plates in various geometry shapes. In addition to the "Rectangle" and "Circle" shapes, the "Polygon" shape is also available. The polygonal shape is defined by entering the point coordinates.