Hey @Dimetrock
Thank you for bringing this DOTS project to our DOTS community as well.
I allow myself post the link for the reference.
Share Our DOTS Showcases page-3#post-8549918
I love trains as well 
As you have already answered some of my questions above, I indeed look forward to more complex and interesting layouts.
Having very long trains can be very interesting, with many attached locos. Long hauling like the USA Amtrack, Santa FE etc.
But please don’t underestimate small challenges, like stocking and joining wagons together on side tracks.
You can even make simple puzzle like game. Well, technically logistics.
Connect wagons in certain order, to deliver them into such and such place. And detach.
Adding challenges timer for loco maneuvers, could add fun playability, washout cratering new complex game mechanics.
It is fun to learn acceleration and deceleration of trains, with different sets and loads.
Arriving to the destination at x time, could bring some scoring. Let be optional. But let people feel some challenge as well, so they wont get bored.
Few things.
Can trains derail?
Can trains crash with each other?
Do you use any physics at all, or just simplistic 2D behavior?
Any tunnels planned?
Will be possible in future to do something like these?
See the time lapse at 10:40