Close duplicates matching any site/url on user-provided list

[leav6]

Essentially, invert the whitelist logic.
Maybe two radio buttons:
O Only close duplicate tabs for the following:
O Only allow duplicate tabs for the following:

I am very interested in the first option (close only tabs matching the list).
Nice to have: If I am viewing a tab at a site that I want to add to the list, offer a button etc. in the extension that adds that URL to the list.

[leav6]

If the Whitelist feature already present is able to do "not" operation, what is the regex or wildcard example to list URLs to close duplicate tabs for?