Hello,
As mentioned in a previous ticket, I think that large planes parked far away from terminal take a very long time to fill by using buses. Part of the reason for this is that the next bus doesn't come until the first gets back to terminal.
Is there any chance you could have it so that more than one bus can serve the plane at the same time? Or at least have it so the next bus queues up to unload but doesn't open the doors until the first bus is empty and leaves.