You may have to wait for 3DX7 as the setup of the puppet has changed and may not be compatible with 3DX6.
Also, IC7 EA is not a full release with all features, but all IC6 Pro features will be available in the final IC7, so nothing is removed.
EDIT: I can confirm that the feature is currently not implemented, as it also does not work with custom face morphs for existing characters.