[Sirensis]

As far as I have understud how it AES works is a simple line system...

a quest consists on parts A, B, C and D.

First group starts of doing part A. Now noone can start part A until the group has advanced to the part B. Then another group can begin the A part...

so at any time there can be a max of 4 people/groups doing that quest.

And pretty sure it will be made so people can't get to parts they aren't part of. So the group doing B part, will be alone at it. (A form of instancing, except there can never be more than one instance, and then it can't really be called instancing can it?).