Hello Greg
First you need to use as much is possible the "Shear Plate" connection which is giving you all the possibilities to create the shear plate and the stiffeners like you need.
After you finish with the "ShearPlate" connection, the other operation you need to do to the stiffeners needs to be done outside of the connection, I mean you need to use the weld preparation tool to create the weld preparation and the rectangle contour for plates to cut the plates to avoid the k-distance (we have the possibility to cu the stiffener straight, concave or convex) but not 2 cuts like you need.