Do you farm EoF during any events or anything like that?
I know headless horseman is quite good for EoF, 14 days event with 2 EoF per day in a super easy and fast fight (I ran 2 dungeons at the same time when doing it, since it requires almost no moving/changing target and almost no damage taken).
Are you doing any other events for EoF or anything else?
I think invasion in Feast of Winter Veil have a chance to drop EoF (or that it did a few years ago at least) but I haven't tried doing it so not sure how hard it is (the fight, other factions 40 man raids be a problem and managing to tag the groups before other raid groups does it) or if it drops much.