Hello,
I have followed the document "How to Extend User Details" to add custom properties to user details. However, although it is possible to add labels to the user details iView (which you can access from KM), it does not seem possible to add labels for these properties on the User Profile (which you access through Personalize->User Profile).
I have checked <a href="https://www.sdn.sap.com/irj/sdn/thread?forumID=42&threadID=129068&messageID=1443674">this</a> post, and the answer refers to the User Details iView, not the User Profile maintenance.
Regards,
Martin