If you open the route using QuickDrive Mode in Driver and place your consists using both the Global Consist Library and the QuickDrive panel you can save a driver session and then re-open it again and make changes using GCL and QuickDrive to the saved session. You can do this over and over again. You don't have to make changes in surveyor to rolling stock if you have upgraded to a version that has QuickDrive available. Sorry I don't remember where it was added but it is in SP2.
There are only a couple of gotchas:
1. You should stop all trains before saving a Driver session.
2. Interactive industries may not work correctly after opening a saved Driver session
