An interesting thought that makes me ask a few questions.
How much of that dwarf planet would be in scope to return? I guess my completely ignorant suspicion is that it would be a small volume of highly valuable minerals, or minerals destined for space anyway.
Also, what about the mass we are moving off world today? Have all of our satellites and rockets and other space bound craft resulted in any measurable change to earths place in the solar system? I would imagine some leave only temporarily, but how much mass do we permanently shed?
What is SFF?