CUE has been an absolute joy to work with on configuration problems. It’s a typed language which is something that’s been a massive gap in the config language space when looking at yaml, toml, json, etc...
The type system also has great second order benefits like allowing us to build an language server protocol implementation for CUE that has rich diagnostics, auto-complete, jump to definition, rename symbol features. Something that cannot be done _as well_ effectively in untyped languages.
I'm still scratching the surface. CUE does more than add types to config and I would encourage you to dig into it if you have spare time. By virtue of providing a great type system, it also manages to reduce boilerplate as yet another second order benefit. Boilerplate reduction is something where tools like Jsonnet attack as a primary goal but over enough time you're back at having seas of untyped config and indirection that are hard to navigate or contribute to and you're back at square one.
Also, imports and dependency management for config will be big