Like any place of gathering, it depends on individual congregations. Most are just very liberal liberals or social Democrats, I imagine. But I really liked the ones I've visited, some more, some less.

https://www.uua.org/beliefs/what-we-believe/principles

I might dare to imagine some congregants in locations farther away may be actual socialist, maybe in other nation-states, but who knows?

They're pretty accepting of any beliefs, from atheist to neo/pagan, including Buddhist, Taoist, satanism (I doubt Laveyan; I doubt anything involving blood sacrifice, but who knows). I don't recall ever having a Eucharist, but it's been a couple of decades.