Consolidation of display names in approval interface

We need to improve consistency of displaying user (object) names vs full names in Approvals (Cases and Work items).

See this screenshot:

The usernames are displayed in the lists, but full names are displayed elsewhere.
This is also visible in "Basic" tab of approval request, where object names (user names) are displayed.

We should probably display fullName (or fullName with name in parenthesis? or configurable?) if such attribute is not null, otherwise only name. Configurable expression a'la summary panel would be also interesting.