Hello,
I'd like to review "Not discovered anymore" items from time to time,
so I can manually delete those where I don't care about their history anymore.

I was surprised I was not able to find a request or even a forum post about this,
because there seems no convenient way to list items in this state.
The obvious way to do this would be a filter for "State = Missing" or "Discovered = Not anymore". For the 2nd option it may help to rename "Discovered" option "No" to "Static".

Cheers