I am only giving Checkmarks 3 stars because while it does work, there are some very obvious flaws with this extension.

I have used Firefox from the start and the old Mozilla web browser before that. I installed Checkmarks on 2 Windows computers and Checkmarks did help me to cleanup years of old bookmarks, but Checkmarks very obvious flaws are frustrating.

Here they are: 1) The interface is not easy to understand. 2) The help is terrible. 3) And my biggest complaint that you cannot clear an old canceled run's output list and start a new run with an empty output list. This extension needs some serious work!

Paul, thank you for your prompt reply. I tried your instructions of "You can empty the result list of a paused run by clicking the cancel/discard button. After that, the play button will start a new run" on 2 computers running Windows 10 and Firefox 77.0.1 (64-bit) and it does not work. When I start a new run, the list is not empty. Yesterday, I did the same test 2 times on the same 2 computers. Obviously, the result list is not being cleared.

Where is the result lists stored? For example, during this process, I also cleaned up my favicons and created a new favicons.sqlite file.