How to customize title bar on constituent page

Kayes Kaykobad

We need to change the constituent title bar so that it displays nickname instead of first name and the preferred class year (From the constituent's education record) at the end of constituent title bar. I've created a nameformat function that gives the desired output but the nameformat function I created is not showing in the dropdown in (Indidual Display name -> Edit). Do I need to modify the page expression view form in order to make this work? If I modify the page expression view form so that uses the name format I created, will users be able to change name format using (Indidual Display name -> Edit)? What is a safe way of achieving this? Thanks in advance