I have encountered a very interesting website using AI to generate in between stages for 2 faces (you can upload your own faces, but they will not be 100% match sadly), which can be used for increased beauty/gender transformations. For example
https://facemorph.me/?from_guid=dc0d...5-894dc59584e2 or
https://facemorph.me/?from_guid=c9f9...8-961da3a4b034