Illager beast AttackTick nbt doesn't do anything when changed via commands

What I expected to happen was that changing the AttackTick nbt to a different value would make the illager beast extend its neck like when it attacks, but nothing happens at all. Changing other nbt data does work though, such as the RoarTick. It seems that data is only used when the mob actually attacks, otherwise it's either ignored or overwritten.