Vibrato control is not included in Special Editions.
While the large VI and SYNCHRON-ized libraries have those, if you like the sound of Synchron Strings Pro go for it instead. I would still recommend upgrading the Special Editions to the SYNCHRON-ized Special Editions, this way you will have them pre-mixed out-of-the-box in a Synchron compatible way, and you can directly use them together with Synchron Strings Pro.
Ben@VSL | IT & Product Specialist