Not sure if this is possible but if it isn't, I think it'd be nice to have.
I set a terminal at my hub as the 'default' contract carrier for passenger service and don't see a way to turn it off. As of now, the only way I know how is to go into each flight number from route management and put the service contract back on the AS handling service. It'd be great to have a way to (or know a way to) turn off the default setting or set the default back to the AS standard.