This is a great Teshuva.
In this Teshuva Rav Chaim David HaLevi offers advice on how a shul should deal with the existence of members who come from varied backgrounds and therefore have different liturgical customs. Rav HaLevi offers some interesting approaches as well a a fascinating ruling on wether or not Jews who only come to shul occasionally have the same rights as those who attend frequently.
But that is not why I love this teshuva. I love this tsshuva because at the end (see highlighted lines), Rav Halevi says that even though the group of regular attendees is correct in their demand to keep the liturgy as is, it should be changed for the Yamim Noraim (high holidays).
Apparently, the group that only attended periodically threatened to not come at all (even on RH and YK) unless the liturgy was changed to reflect their custom. In the interests of making sure those Jews remained connected to the shul, Rav HaLevi recommends a temporary change of custom!
Such an approach illustrates 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.
Follow this link to read the entire teshuva.