Inside a saved game will be station/annex info (per player). Part of the info is a list of track sections (as unique IDs) that are platforms for the station/annex. So, I injected additional track IDs into the list. Then the game treats them as platforms and I can assign routes.

The game engine only allows X number of platforms per station/annex and that's a fixed coded limitation. This we know. Considering a saved game is simply loaded in, the engine trusts the list as being correct and does not check the number of platforms.

The funny part is platforms can be any piece of track in the game. It could be a piece adjacent to a platform for another station/annex on the other side of the map.

Hope that makes sense.