Seems to be an acceptable browser extension. Just a bit curious as to why it would detect no malicious links on Firefox, but would detect 78% on both Edge and Chrome.
FWIW As Fabian came here to explain on occasion, Emsisoft tries to set itself apart from the competition by not submitting whole URLs back to the cloud, so it's probably not performing as well as some of the others just because the cloud doesn't get to analyze live URLs in realtime.