The big news in the Stable Diffusion land has been the release of ControlNet: https://github.com/lllyasviel/ControlNet. It hasn't gotten much traction on HN: https://news.ycombinator.com/item?id=34761780. It allows you to maintain the shape of existing images (or sketch new ones) and use Stable Diffusion to fill them out, my example: https://twitter.com/LechMazur/status/1626668677473918981.