Shape Splitter/X-Morphs Making the Promotional - Smoothing

I created a character morph but it's face is very asymmetrical. I am wondering if I could use this to choose one side of the face to mirror to the other to make it symmetrical. I watched another video you have that I believe was about making a face symmetrical using weight maps but the resulting face doesn't resemble the one I started with. I cant tell if it is averaging both sides or just reverting back to the G8 base face.
Please let me know if this is possible and how I can do this if so.