The "close duplicate tabs" option was a great addition to my opinion. I regularly have around 1000 tabs open and when I get to clear some of them it becomes a hassle.
It will be great if you can also:
1. "close all tabs of this domain" - this can clear many tabs for websites that no longer exist or if there are the same, but a bit different. Like google searches, google translates, etc.
2. "sort tabs by the current domain" and/or "sort all tabs by domain" - this way you can quickly review what you may look for, without going back and forth between tabs. Let's say 100 facebook pages and youtube videos can be checked quickly, so you close what you no longer need.