They have the capability to item level sync, instead of level sync. The issue is that when they do this, potencies of actions are not synced down.

Let's use Sastasha as an example. A PLD's actions do, on average, 200 potency damage.

If they could use Holy Spirit, they would have phases of doing 380 potency damage, which can be combined with Requiescat to make that even worse.

They would have to develop a way to sync down the potencies, such as by a percentage that is the difference between dungeon's level and the action's level.