Setting Object Variables on a Prefab with Manual Event gets reverted on Play

[AiSard]

Used Manual Events to set a bunch of Bolt Object Variables on a Prefab, only for it all to revert when entering Play Mode.
Finally got around it by using EditorUtility.SetDirty on the Variables component.
Same thing happens for a Variant Prefab, but not on a non-prefab.

Hoping there's a way to ensure anything that Manual Event touches is marked as dirty so that it will serialize on play?