Special:Redirect should be able to redirect by page ID, as well as revision ID and user ID.
Granted, this can be done with the URL parameter curid; but that is not discoverable.
This could help for bug 21572 as well - you could set up a rewrite, say from mywiki.example.com/123456 to mywiki.example.com/wiki/Special:Redirect/page/123456
Version: unspecified
Severity: enhancement
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=21572