Unfortunately this is useless for filtering out terfs, because while it does an okay job at identifying obvious Anti-Trans people, it also marks TONS of clearly trans positive trans and intersex people as "Anti-Trans" for really ridiculous reasons.
Mostly it seems to target trans and intersex people that use contradictory labels (or seemingly contradictory labels) for themselves. I don't think it's a great idea to assume how someone thinks about trans people based on the words they use. Since terfs co-opt our terms ALL THE F-ing time.
At this point the extension is no longer a thing that keeps the trans community safe online, but instead a thing that divides us.