I have to admit, that I did not have too close a look at OACS 5.0. The thing is, the smart URLs part has been done by Tilmann Singer, who - as far as I know - adapted your code from Greenpeace. Our implementation does not distinguish subsites.
The package is not properly finished as such. As it was developed for UNIDO it is tightly intervowen with the unido content package, and as I learned that there is an i18n coming up with OACS 5.0 there should be no need to do such a package twice.
If I can be of help in any way, let me know.
