Thanks for sharing! We had a slightly different cost/benefit analysis for our use case with fairly straightforward APIs but know that might not be the same for everyone.
If you already have a different source of truth (like protobufs), then other methods will make more sense. We think CUE is a great language for the source of truth as it has integrations with all the common config formats as well as tech like protobufs and OpenAPI schemas. It's also much nicer to express large amounts of declarative code in.
Anyway, thanks for sharing as well! I found your perspective quite interesting too. I have some desire to see something like JSX for our CUE+templates, but that is still quite unclear and a long-term vision