This is a great hack, though I did need to uninstall it to deal with some other issues, and i noticed that it would not remove the entries in the settinggroup and setting tables. I examined install_warning.php, and noticed that the group id when installed is set to 40, but the group id is set to 44 in the uninstall section. I'm not a MySQL guru, so I may be wrong, but should this not be 40 as well.
Like I said, great hack, just thought I'd point this out ... unless it already has, in which case, I'm sorry.