Curves tracing

Two extension come in mind, Weld for combining the loose edges of the curve and perhaps Simplify Contours to downsize the edgecount.
As mentioned, they work in the ‘context’ of the imported component, so you would have to open it.

Mind you, selecting an imported .dwg can be tricky since you have to select an edge of the component precisely, rather then ‘somewere in the bounding box of it.
Zooming out makes it easier to double click and enter the component for editing, I’ll find.