If you reach the destination, you sometimes want to drive around manually. If you switch to manual mode on reaching the destination this is made much easier, and if you click a station in the list to go there it will switch back to automatic anyway.
I made it so that when a shuttle-launched (by the UI or keycombo) train stops at a train station and has exactly 1 train station in its schedule, it switches to manual control.
One side effect to manual mode is circuit networks for the station do not report train cargo in manual mode. Took a while to figure out why my reloading logic broke when summoning the train back to my base. Not asking for the change to be reverted at this time.
