Preferential marks a slot whose enchants add nothing these weights can measure, such as Leech or Speed, so pick the one you want.

No gem or enchant here was simmed: SimulationCraft can’t sim healing. Each list is in order of what an option’s stats are worth under the weights on Stat Priority, which come from what top Mythic+ Holy Priests run. That gives an order, not a gain to print. A weapon enchant’s stats come from a proc, so they count for the 58% of the fight its buff is up.

An option whose effect isn’t a stat, such as a bigger crit, has no estimate: the weights can’t see it. Some carry a note on what they do instead, and a few of those are hand-picked to lead their list on that effect.