Is Yandex Wordstat Assistant safe?

This extension builds and copies phrase lists with frequency data from Yandex Wordstat.

It lets users add phrases from the old or new Yandex Wordstat interface, copy the collected list to the clipboard, and paste it into a spreadsheet editor. The phrase list persists after the browser closes, syncs between open tabs, checks for duplicates, and can be sorted by add order, frequency, or alphabetically.