So the base session can never be updated with changes made during in game changes. It seems to me that this eliminates this version from route development if you always want the session to start out at the same place. To illustrate the point at the extreme. Say I have 10 consists that I have routed to be consumed by portals in say an hour. I start the game and make changes in stuff and then save. I then restart the game using the new saved session and make some more changes. If I repeat this process several times all my consists will have been consumed by the portals and I have nothing left except a route and session with no consists at all. Game over!
So how does one developer make a route to share with others? With this version if it is intended that the session begin at the same starting point but now every time a change is made “in game” the starting point keeps changing. In this case the base session does no good since it does not reflect the “in game” changes.
The "base" session still exists. You can go in and start over just the same. What's occurring while you are editing the session in operation is you are editing and saving changes to the base-session -- the one that we could never edit while in Driver. The changes made there, while the trains are running are saved back to the route and session, but the moving trains are not.
I say this with experience using my Gloucester Terminal Electric route as an example. I have two sessions setup for this route now. One session is for freight operations with most of the trolleys sidelined at the terminals for about 3 hours in the morning before they start their busy schedule. There are still some running as regularly as the passenger-oriented session, but it's a mere handful in comparison to allow the freights to run the line to pick up and deliver freight to the online industries not located on the freight branch.
With the setup running, I discovered that I had a switch-lever missing on a siding I had modified off of a branch to another warehouse, went off to the edit mode, fixed the switch, and continued on where I left off. In the olden days, we would have to stop the operation to do the editing to fix this error. After running for over an hour, because I switched other industries and freight cars in the yard as well, and then drove the line only to find the missing switch. As you know this becomes quite frustrating as other things usually pop up as we move down the line during testing and we end up repeating the process over and over.
The changes here were saved to the route as a normal thing, it also asked me to save to the session which I did anyway, but that was saved to the base-session as you call it and not to the driving session as I would expect. Later on I quit my driving due to me derailing and getting really tired, and I didn't save my driving-session. The next day, I started my session from scratch after loading up the freight-oriented session again. The junction lever was in place as expected, and the consists were all where they started in the first place.
