In the examples it looked as though there is still a CUE unification loop happening during dagger processing:

  deploy: netlify.#Deploy & {
    contents: build.contents.output
  }

It looks like dagger is using cue as a bit more than a YAML replacement; it hydrates cue values as it runs - which is cool! - but that's the part that seemed at odds with CUE's philosophy of pushing nondeterminism into clearly marked files.