Follow this link to a blog post I wrote on a fascinating Teshuva written by Rabbi Chaim David Halevi. This Teshuva is a great example of the appropriate use of what has become known as meta-halachik concerns. All the halachik evidence is in favor of the main group, but, nonetheless, Rav HaLevi recognizes that there is a larger issue and is willing to adopt a bi-dieved (non optimal) position (praying with liturgy that is not one’s custom) in favor of maintaing the connection of the the marginally committed.
Witness A Great Posek At Work! – Rabbi Barry Gelman