'Show saved Filter': offer the ability to edit Columns displayed in the preview

he columns displayed in the "Show saved filter" portlet are hardcoded, depending on the issue type.
It would be nice to be able to customize them, in order to have the info we want directly from the dashboard.
For example, for the bugs/features opened on the current version, I would like to see the assignee, and not just the ticket id/description/priority.