Indeed, but my larger point is about how the protesting could backfire, not how it could lend publicity. The Steadfast people are extreme outliers in American Christianity, even very conservative American Christianity.
You would have a very hard time walking into any Baptist church and finding anything like that kind of overt hatred. Evangelical Christians in the United States are very good at wrapping their messages in love, no matter how toxic the messages are.
So I don't think protesting Steadfast accomplishes what you think it would accomplish. Even if you get a few conservative Christians questioning the hate, when they walk into their own church and hear their own pastor preaching a very different message, I don't think you'll have accomplished anything. You might have actually accomplished the opposite of what you intended, by giving that questioning conservative Christian internal moral cover. "See, we're nothing like those awful Steadfast people."
It conservative Christian churches in the United States were actually preaching violence against LGBTQ people, then protesting that to expose it would be very important.
But they really aren't, with the exception of a lunatic fringe group in tiny numbers.
I'm just saying that if you're going to try to protest that to equate conservative Christianity with calls for violence, you're not going to be doing anybody a lot of favors. Because people can easily see that that's not really what's happening.
I just think it would be better to target fundamentalist Christians with messaging about the toxic and very real, very harmful things that fundamentalist Christians are ACTUALLY doing.