I'm not aware of any no agreement to put zed lo tkt holders in biz elite on DL
Interesting question!
If you fly S3 anyhting (so how is that a zed--are you sure it's not a yield fare?) you'd be technically ahead of S4 buddies but they have the right to business class and zeds don't (unless you have something in writing??) hmmmm--maybe there is more to this??

I have not seen any zeds forward lately on INT travel routes, so I doubt you should count on it. If you're flying zed you shouldn't have any connection priority over emp pass riders, should you? I'd call your pass bureau but I don't see how zed gives you S3anything? That doesn't seem correct (as in that's not really a zed, it's another type of pass?)
Our rules state zed low on partners is still zed--below buddy passes and coach only.

Please let us know what you discover. Thanks!