The Satanic Temple is actually really bad at "their thing." They lose the majority of their cases and their primary attorney has been repeatedly sanctioned. They're 1A grifters.
If you actually care about 1st Amendment protections you should be supporting groups like FFRF or the ACLU instead
Yes. That ACLU. If you're more focused on the establishment and exercise clauses you should donate to FFRF. If you're concerned with First Amendment issues generally you should donate to the ACLU.