Unfortunately, using the ‘angle between normals’ slider mainly serves to reorient the shadows, or something- the ribbed lines remain unaffected. And same goes for the ‘smooth normals’ selection.
Collada files can be troublesome. They often have a weird hard shell of edges that is difficult to remove, it’s like a second set of edges that are not attached to the faces.
But usually exploding the group will allow them to behave.