Tested in DM:
The Rib feature does not allow a center positioning of the created volume along the input profile curve.
In the screenshot you see that the directions and spacing is off:

Also FUsion does not allow you to do ribs when selecting a sketch that includes many single non-connected lines.

I really do not want to select all lines.
So if I connect them like in the first image I would need the spacing to be centered along the profile.