I left BN in 2000. In 2009, I went out for a visit. I couldn't believe how much Plano and Sanwich had grown up. New subdivisions were where corn fields had been a few years before. This would compliment the extension on the C&NW to Elburn.
As to Rockingham's comment about track layout, this would need improvement. Track 3 would need to be replaced between Eola, and Aurora. If I recall correctly, the Montgomery crossovers were slow speed. It was signaled with a Restricting indication. The slow speed crossover was bad enough, but having to go restricted speed for the whole next block is no good.
How to handle the servicing of the trains is a problem too. A job would have to leave the Hill Yard, then change ends, and head west. The time of changing ends would tie things up good. How would Sandwich trains handle an Aurora stop? Could new platforms be made up on the main? They could put stairs, or an escalator from ATC?
Another point would be whether the trains would deadhead from the Hill Yard. I mentioned the problem with that. If some of the trains were held over in Sandwich, than a whole additional staff of coach cleaners would be needed. They had some mechanical staff in the Hill Yard. This was a good insurance policy, in case of emergency. A good example was one time when our cab car had a cab signal failure.