This blog demonstrates how you could apply different formatting to a person or group type of column in a SharePoint Online list. With column formatting a last name, first name format is applied.
Again a blog about list formatting in SharePoint Online. This time I am trying to create an alphabet filter for a list with client names. This solution is also using dynamic filtering feature.
Recently Tetsuya and Michel shared some great examples of a new option in List formatting. You can now use a setValue action within List formatting.