Hi Harpsi, thank you for all your hard work, it is appreciated
I had a suggestion for the two biggest KORD residents, AAL and UAL. I think no matter how many gates they have, you will always have planes scattered arround the airport cause these airlines have more flights scheduled than they have gates for! (Normal ops at the US of A. I've waited hours for gates!)
Anyway, I think a realistic solution to this would be to make relief gates for these carriers at their respective Maintenance ramps. Both American and UAL have maintenance hangars/ramps where this could be done. And as a last resort, you could make some uncoded parking gates at the hold penalty box locations through-out the airport. This is where ATC puts you out of the way as soon as you find out from Ramp Control that your gate is occupied.
Hope that helps.
Mariano