Add Support for Contact movement between lists.
Contacts cannot be "moved" from one list to another. If you mark a contact as Deleted, they are completely unavailable.
Allow delete of contact by specific list and not all lists. Allow movement between lists.
I do not know the schema for your database(s). Perhaps you can add a view that includes a compound key of email and list name.
It is particularly harsh that a deleted contact is removed from ALL lists and cannot be added to another list. I assume this is a schema related issue.
Thank you for your suggestion.