Although U-Bahn stations in Berlin don't have directly visible track numbers, it would be helpful to get them from the API, in a handful of situations:
should station maps ever become available, the track nr would definitely help
to let people make estimations on how far two tracks are apart
For S-Bahn trains, track info is available.
Apple Maps already has information at with stop to enter/exit the train:
Closing this. Because hafas-client covers multiple endpoints, it shouldn't have too much endpoint-specific logic. vbb-hafas/bvg-hafas can easily add this.
Although U-Bahn stations in Berlin don't have directly visible track numbers, it would be helpful to get them from the API, in a handful of situations:
For S-Bahn trains, track info is available.
Apple Maps already has information at with stop to enter/exit the train: