Suppression list for Lead Finder

I see requests to remove already exported contacts from search and this is crucial but it should be noted this should include all contacts in campaigns and not just those downloaded from Lead Finder. Most of us have been using other lead sources for quite some time and I can't justify moving to Lead Finder until I'm sure I won't be wasting tens of thousands of credits for duplicates.

A less elegant but still useful feature would be adding a suppression list where we can import a list of emails or domains to exclude. While it requires more effort from the users, it has additional benefits: allows us to remove current clients, companies that want to be removed from the list completely, etc.