Right-clicking another tab and selecting copy urls copies the url either for the active tab or the selected tabs, a little confusing in that case but otherwise the extension does what it sets out to do.

example: I have three tabs open: this page, reddit, and bluesky. I select the tabs for this page and reddit by holding ctrl and clicking both, when I then rightclick the bluesky tabs and choose copy urls the output in the clipboard is "[this extension page]
[reddit]" and not "[bluesky]" as I might expect.