They need base setting with a tool that even the dealers don't have - I have heard of workshops that fitted just the motors running into difficulty as they can't base set them.
If the full plastic manifold runner with motor already attached is purchased it has been set at the factory & no setup is required.
V6 TDI turbo actuators suffer the same basic setting issue - if the full turbo is bought it is base set. If just the actuator is bought it needs setting with a specific tool that no dealer appears to have.