sweep section along multiple lines

Hello,

I have a Rhino model with many lines (the reason of this important number of lines being that the structure software I need to use afterwards does not work well with curves).

I would like to create a tool that allows the user to draw a section (closed polyline) in Rhino somewhere near the model, and applies it to all the lines of my model (thanks to Sweep1).

My problem seems to be that all the local axis of the lines are not in the same (and proper) direction, so my beams are upside down. In fact, I need the local axis to follow the surface normal of the corresponding Area, and the flange to be upwards.

I am looking for an idea to homogenize the local axis of the lines so that the Sweep1 function leads to the right orientation of the section on all the lines.

Or maybe Sweep1 is not the best function to do this tool?

Thanks you for your help!