The person behind nitter.poast.org, as seen here, has been outed as some reactionary former dev of 4chan: https://accollective.noblogs.org/post/2021/06/18/admin-of-poa-st-anime-graf-mays-revealed-daniel-stevens-of-ontario-canada/ (CW: racial slurs)
He is also the admin of Poast, which is a reactionary instance on the Fediverse, reactionary to the point where even MSM had articles about it.
Needless to say, I'm going to use another Nitter instance (nitter.esmailelbob.xyz) and I would encourage others to do the same. Here's a list of Nitter instances: https://status.d420.de/ in case nitter.esmailelbob.xyz turns out to suck as well.
Edit: Damn, it turns out esmailelbob sucks as well lol
Oops, I blindly copied a Poast Nitter link recently and had no idea--thanks for the PSA!