Will you add http://unix.stackexchange.com to the list of available migration sites which are suggested whenever someone decides to close the question as off-topic?
I also wonder if an option to manually specify an SE site would be of any use.
Jeff has stated that there will not be more than 5 migration targets:
If you really think a question would be better off on a site not on the list flag it for moderator attention giving the site. Moderators can migrate to any other site in the network so if they agree it can be moved.