It would be nice to add a "black list" option or some other similar filter to your fort to exclude exactly who is allowed to pass through it. There are some allies who come and take cities within contours that are unwanted, and usually these are political allies (e.g. a member of an allied order).

So, it would be nice to have an "order only" and preferably something like an SQL search to specify EXACTLY whom is allowed to enter your fort.