I’ve never been able to get the groups to work as per the wiki if enhanced security is on. I’ve gone through all the motions of setting up groups, chgrp of the directory and files, make a symlink from the new user’s account to the directory I want to share, etc, etc, but no go. Permission is always denied unless I turn off enhanced security, which I don’t want to do. The way around it that I found a while ago (but might have forgotten) is that I turn off enhanced security for the other person’s account, and then I can go in, chgrp on the uploaded files, then move them over manually. I kind of gave up on the idea after a while.
I’m still learning, so please don’t take this as advice.