Marked with the red circle.
I want to make a smoother transition between the two ramps but I never knew how to fillet an edge where two polysurfaces connect.
191025.3dm (7.9 MB)
One way is to trim with 2 _CutPlane objects, then use _BlendSrf for transitions:
Next time only save the object in question instead of your whole project 
191025_SG.3dm (145.1 KB)
btw: the U-shaped surface is not very fluent, but I left it like it is.
Thanks for your answer!