Yeah this is very varied. I am a part of a reformed tradition. I’ve seen tracts from my church concerning Catholicism and their plan for salvation and how what they believe is wrong. I’ve seen a family very upset with a daughter dating a Catholic young man. I’ve been in the membership class years back when they taught us that the Catholic perspective on the Eucarist was wrong and like cannibalism, and how mass is very pagan, full of secularism. I’ve also had friends visit Rome and avoid the Catholic stuff or say that it was sad when they saw pilgrimages.
Overall, many of them are earnest, misinformed, or very stuck in their own tradition. But my cousin attends a non denominational church and I think she is open to Catholicism. Our mothers’ family is Catholic and our fathers’ is agnostic or Protestant, so that is probably why.
My husband was anti Catholic when I started discovering the Catholic Church, and his family was Catholic, sort of. His parents who are non religious nowadays disagree with the Catholic Church a lot but then they don’t even understand much nor care to be informed. I think that is what most people do. But I am happy to report that after a few years, my husband’s heart has been opened to the Catholic Church. He told a friend about it but his friend was very concerned for my husband and sent him about 10 YouTube videos showing why the CC is evil. He’s a rogue Christian and doesn’t believe or trust any tradition, especially the CC. It’s bad though because he doesn’t believe in the Trinity, the holy spirit is not a person, and he can’t seem to make up his mind about the Sabbath being on Saturday, Sunday or based on a lunar calendar? It’s just chaos. There are many Protestants who need prayers to find the truth!