Continuing on with the idea of getting insight into the Essbase feature set over time, as viewed through the lens of its Essbase Java API evolution, you can quite clearly see that the open/URL-style drill-through (as opposed to classic LRO-based drill-through) showed up in version 11.1.1.3, which in fact is pretty much the only thing that seemed to get added to this particular release, Java API-wise, along with some ancillary drill-through methods/functionality in some related classes.

More near to my heart: this is the exact functionality that paved the way for Drillbridge! Although it wasn’t available as a feature on day 1, subsequent versions of Drillbridge gained the ability to automatically deploy drill-through definitions to a given cube, and it uses exactly these API methods to accomplish it.