I imagine something as large as a railway is already covered (especially with the railfan community). In fact in most locations they actually include the number of tracks, passing loops and other features that a simple GPS track will not have.

Why not? It is always informative to have more information. Especially if you know ahead of time, what side of the train to be on, to see more interesting things. Also having information on one map program is great. Why switch apps? Especially since OSM is so privacy friendly.