No Options Rated 1 out of 5 stars

There is no obvious way to start it. You must open add-ons, find the extension, click on preferences, then click on start. It then says, the following bookmarks will be deleted. Is it deleting the first one it finds? Is it deleting similar bookmarks? There is no option to choose which bookmark to delete. What if I want to delete a duplicate from an imported bookmark folder? It's nice that it requires no restart, but there are better duplicate bookmark add-ons.

This review is for a previous version of the add-on (1.2.1-signed). 

Thank you for your feedback. I understand that you find the way this addon is used inconvenient, but as it is intended as a single-use (or at least rarely used) addon, it should be no big issue to navigate to the Addon-Manager.
Furthermore I think one-star-ratings should only be given to addons that do not work as described, not when it lacks personally desired features. If you have feature requests, you can always write an email.