Rated 2 out of 5 stars
This is an excellent addon but it seems to be broken of late (previously rated at 4). Press manage seach engine freezes firefox in Linux. Try to go to prefs and managing the searches from there yield no better results.
I've gotten around the bug by unhide mozilla native search ui and managing the search engines from there. not ideal/
It would be my pleasure to review my rating should this bug be fixed.