Unity: 2017.4.28f1

The above build of the SDK is missing several triggers from VRC_Trigger including:

OnStationEntered, OnStationExited & OnDataStorage

I created a new unity project to test and I still does not show those options. Here is a screenshot of the options given with the chair prefab.

Edit: OnStationEntered & OnStationExited do appear on objects that do not have stations.