Import a standard CC character into unity. Setup the character with humanoid type rig. Create avatar from this model. Import a CC+ character into unity. Setup the character with humanoid type rig. Use avatar previously generated with former CC character. CC+ Character will be distorted and malfunctioning in unity when animated.
Why this matter? All work previously developed with CC characters needs to be compatible with the new CC+ characters. This means that the bones of the skeleton will need to have the same rotation values otherwise the humanoid rig will malfunction. If you check the pelvis bone for instance on a CC+ character you will see it is very different from the CC characters. It needs to be the same.