I don't speak Esperanto yet but I think it might be a good thing to have a community for, given the language's internationalist nature and its historical connections to left-wing politics. If you look for federated Esperanto communities, one of them is basically locked because they moved instances, and the other is dead as a doornail.

An Esperanto comm could be used to talk about Esperanto history and culture and news from Esperantujo, or help people learn the language, or people could discuss language politics, et cetera, all in Esperanto. Hexbear does have that weird thing where it won't let you post if you say that your post is in a language other than English, though.

An alternative might be to see if there are any Esperantist instances we can federate with.