Earlier quoted context omitted.
Just for reference, here is the metaprompt I first gave to Opus: “I want to ask Claude Code to write a browser-based synthesizer for me. Please prepare a prompt for it that I can give to it for it to write the synthesizer. The synthesizer should automatically create interesting polyphonic music in which the various voices play off against each other in both harmony and contrast. The controls will affect the tone, rhy…
You'd probably get better results giving the metaprompt to Fable. Information doesn't magically get created, running something through a dumb model to give to a smart model gets worse results than if you just give the smart model the prompt directly.
I should mention that Fable also did an impressive job on a couple of major project-redesign tasks I gave it. Those aren't things I can share here, though.