I haven't found more than that yet but I've started work on some examples with documentation to demonstrate what's possible to help get folks started with Meta. I can share it very soon! It's all going here once it's ready:
https://github.com/mattmoore/kotlin-compiler-plugin-examples
Repo is currently empty but I've got some examples running locally. Just need to touch them up and write some docs, then I'll be ready to push. Probably this weekend. 🙂