I would like TSW2 to include a fictional yard/train museum that has sections and track that can house every engine and all the rolling stock in the entire game. It would have a saved state that would allow you to drop in and move some stuff around or make up a train and then maybe drive it for a quick excursion around the grounds. Come back next time and everything is where you left it. I would imagine adding a new section for each DLC that resembles the dioramas and is made up of existing assets, but still make them all in the same physical space. Add support for all electric power types and let us just play around with our trains. Kind of like a 1:1 scale model layout you can walk around in.
Yep ... like the "Siemens Mobility Test & validation centre" at Wegberg-Wildenrath, Germany. Seen from above, it looks like a model train starter set track. More informations: https://en.m.wikipedia.org/wiki/Test_and_validation_centre,_Wegberg-Wildenrath