Several benefits come with graduation, including the ability to set up migration paths to and from the site. This would entail a close option under close -> off-topic -> belongs on another site, which currently only has meta.PPCG as an option for non-moderators:
If three or more users vote to close using a "migrate to Stack Overflow" option, the question would then be locked and eventually deleted here, and it would immediately appear on Stack Overflow just like a normal question.
The most likely migration target for now is Stack Overflow. Should we set up a migration path so that regular users can migrate off-topic questions to Stack Overflow?