Can you look at lowering the runway maintenance cost or better yet reducing the time the runway degrades. See very excessive at the moment.
Also, just like in real life the airport operations would be able to make stand, service car, airside shuttle bus changes. Currently it is near impossible to change linked service cars and shuttle buses to a new stand without totally shutting down operations. If one wants to add an additional airside bus stop and change a currently linked stand it is not a simple task at all.