There are also super interesting overlaps with anti-Spiritualism and anti-feminism - cases of husbands trying to have wives committed because of seances, and Spiritualist circles physically fighting them back, that sort of thing.

The progressive component is definitely a part of Spiritualism as I know it. Worship means thinking hard about physics, metaphysics, and ethics, reading widely in spiritually serious texts and then discussing them in groups, often with women in central positions. And then going out and trying to live up to ideals through social service and political advocacy. And nobody ever goes to church, or makes too much of a fuss about spirit things.