VL's have rules that YOU created in the first place. It might be a Tag. It might be a column value.
To add a book, make it comply with your rule.
To remove, make it fail the rule.
EG this is my TBE (to be edited my way)
Code:
#finished:false and formats:EPUB and #edited:false
#finished must still be false (why fix a book you have read, when there are unread books to clean

)