Hello Emanuel, l am in fact trying to do exactly what is described in the link you refer to. The Fiori Leave Request app does have its tile available in the launchpad and when I attempt to create a leave request in the app it does get created in the backend. The WS30000015 seems to be ideal as I will then have the BOR object for leave requests avaiable and no major modifications are needed for my purpose. How does it work in your scenario? I can configure any workflow I need in the processing process for leave types configuration.
I found this document that seems to describe a scenario similar to my need, here:
http://scn.sap.com/docs/DOC-46215
Best regards,
Anders