yes, I've already tried this.
it is easy to move the metal quads and triangles to a separate file and then apply edger 2.
the difficult part is,
getting rid of these (now superfluous) edges in the original file.
many of them are e.g. optional lines, and cannot properly be selected with the mouse.
others prolong and don't share coordinates with quads, but instead extend from metal to plastic parts,
so they need to be shortened, not removed.
this is where I gave up :-(
it is easy to move the metal quads and triangles to a separate file and then apply edger 2.
the difficult part is,
getting rid of these (now superfluous) edges in the original file.
many of them are e.g. optional lines, and cannot properly be selected with the mouse.
others prolong and don't share coordinates with quads, but instead extend from metal to plastic parts,
so they need to be shortened, not removed.
this is where I gave up :-(