Simple idea: Train waypoint station. A small station that you could place. Could be used side-by-side for a siding for example. This waypoint station CANNOT have any modules attached, it only allows trains to go to it, or wait at it if the train can't currently go to the next station.
This would allow to, for example:
1. Make sidings take up much less space (sidings where trains will wait if they have no jobs for example - sidings that require stations, sidings for evading stopped trains don't need stations)
2. Make waypoints smaller, since you need a station to make a waypoint right now
3. Possibly more?
More shown in the image
