1.21.1

The entity type tag "blacklisted_from_spawners" should prevent entities from being captured and used on a spawner by the Ender Lead, but it does not.

Ah, I guess I misremembered my own setup when I was talking about this. blacklisted_from_spawners prevents the occult ender lead from applying the entity to a mob spawner. To prevent capturing, the standardized neoforge:capturing_not_supported tag is used instead.