I sectioned this arched extrusion at the angle I wanted for a miter joint…
Problem is, I can’t shake the section symbol lose (even after I explode it and make it its own component).
How do I free the new model from this extra baggage?
Separately, is there a better way to chop a miter in a shape than this method?
I wouldn’t have thought of using a section plane for something like that. I’d just select the geometry and make the components.
Depending on how you made the molding you might need to edit the components and add faces at the mitered end by tracing an edge with the Line tool.