After watching Boston- Providence preview I imagine that in London route on Brighton station there will be trains coming from/going to Hastings and Seaford and like they said in Boston- Providence preview we wont be able to ride/drive them. But it could be awesome if when trying to board those trains we get a prompt "Would you like to load this service in East Coastway?"
I think that something along these lines should be DTG's next major project. This will act as a form of route extension where currently applicable.
That's a great idea! It's like a shortcut, which skips the painful process of switching multiple menus. Instead, just click a button and go to another route in the same train/time with the same weather settings! If combining routes won't be possible, this is the best alternative.