Given that you'd also want or need build logs, artifacts, etc., and for some projects this is easily tens or hundreds of GB of data, this could well be very time consuming, requiring considering things like retries and resuming transfers. (Granted, maybe not for you, but generally speaking.)
Also, since build.xml files aren't exposed like a job's config.xml is, this will require massive changes in the plugin.
Note that some plugins also store data in additional files (Promoted Builds and Subversion come to mind) which would also need to be considered to result in perfect replica. In comparison, it's trivial to just transfer the job folder over (+ Reload Config on the receiving side, delete project on the sending side) to get the same result.
While I'm not a job import plugin dev, I have serious doubts about the feasibility of this.