I can't seem to find this anywhere. Has it been withdrawn or has the site restructure just hidden it somewhere? I'd like to do some testing with it.
The custom option module we did was removed because, aside from threading issues w/ PHP, there is a huge root security issue that the module site itself outlines:
apache2-mpm-itk under "Quirks" oddly enough
"Since mpm-itk has to be able to setuid(), it runs as root (although restricted with POSIX capabilities where possible) until the request is parsed and the vhost determined. This means that any security hole before the request is parsed will be a root security hole. (The most likely place is probably in mod_ssl.)"
That being the case it is not very likely that we'll provide one in any form.