If you wanted to, you could either add a specific tag or a metaproperty option. As you find them, classify them as that, then delete them in bulk. 

When I do find a duplicate occasionally, I usually just delete it right away. But if you needed time to investigate the duplicates (i.e. are they visible to different user groups, do they (somehow) meet a different need even though they are visual copies, etc), recategorizing them would would allow for you to always come back to them at a later time to investigate further. 

My understanding is that the duplicate finder is checking for duplicates upon request. In the case of the new AI package, its upon upload, but only the assets being uploaded are checked against the whole library.