RIR Inconsistent beam orientation

I’m using lines to place some beams in revit but their profile orientation is inconsistent.
As far as I can tell there is no meaningful difference between the lines and I expect somewhat consistent orientation of the profile in plan. The problem is that I need to rotate them afterwards (changing the cross-section rotation parameter) but cannot differentiate between their initial positions. I couldn’t get anywhere using Element Location component.

beams.gh.rvt (704 KB)
beams.gh (13.2 KB)

Using an Line SDL provides a consistent start point for the line. Controlling Rotation on a curve can be tricky (it doesn’t inherently have a rotation base plane)

I understand that, but my curves have consistent start end points, consistent direction, yet the result from the beam component is inconsistent.

Maybe you can check if the curve frames are consistent or not ?