TL;DR
Filtered slots will not be trashed when trash unrequested is turned on, unless you set a logistics request with a maximum limit and the item exceeds said limit.
What?
Basically, whatever is in your filter slots will never be auto trashed from the trash unrequested toggle, regardless if you have a logistics request for it or not. In order to trash the items in the filtered slot, you can simply remove the filter or put the items in the slot into the trash slots manually. If you have a logistics request for the item with a maximum limit, the excess items will still be auto trashed when that limit is exceeded. i know you could just set a request for the item, but that could be something you do if you want to, rather than being forced to.