Can I filter a saved view by Done or Ignored status?
No. The Status filter in saved views supports only Todo and Snoozed, plus their sub-states such as Waiting for customer and Paused for later. You cannot filter a saved view by Done or by Ignored.
Plain has three thread statuses: Todo, Snoozed and Done. Ignored is not a separate status. It is a sub-state of Done, so an ignored thread has the status DONE with the detail IGNORED.
To see Done and Ignored threads, use the default All threads section. They cannot be isolated in a custom saved view.