Mormons don’t do rote prayers. I feel like this was a central teaching in my upbringing. We weren’t like the other Christians who foolishly just said the Lord’s Prayer or recited the 23rd Psalm over and over. We said each prayer new from the heart, at least in theory. Related to this, does anyone else recall how stressful it was to give the closing prayer after a lesson on prayer, because you had to try extra hard to make your prayer original?

The scriptural support for this position isn’t hard to find. Our go-to is of course Jesus condemning praying with vain repetitions like the heathens in Matthew 6. But we also have the bad example of the Zoramites in Alma 31, who not only dissented from the true church and gave a self-aggrandizing prayer on their Rameumptom, but all gave the same self-aggrandizing prayer. (Not surprisingly, only the Zoramite men got to do this, as the women probably weren’t chosen by God in quite the same way.)
Of course there are exceptions to the rule. We have prayers for ordinances that are required to follow a script. The sacrament, baptismal, and temple ordinances are all like this. And it could be just me, but I feel like the emphasis on this principle has declined in my lifetime. (Or it could be that the emphasis was, to begin with, particular to my ward, or even my family.) Also, perhaps coincidentally, I’m happy to see bishops in wards I’ve lived in appear to become much more forgiving when a priest stumbles over a word in a sacrament prayer. When I was a priest, decades ago, I feel like nobody got away with even the tiniest error without having to re-say the prayer.