How Relevant to the United Kingdom are the 'Religious' Cases of the US Supreme Court?

High-profile cases in the Supreme Court of the United States ('SCOTUS') on religion tend to attract a certain amount of academic comment in the United Kingdom but US judgments are cited only infrequently by the superior courts in the UK. In return, SCOTUS rarely cites foreign judgments at all. The reason, it is suggested, is that the effect given by the First Amendment to the US Constitution is to render US case law of less relevance to the UK than, for example, judgments from jurisdictions such as Canada and Australia.