It is interesting that Fable 5.1 max [1] which also produced a decent pelican with 65k output tokens compared to 5.5 running out of 128k output tokens tells us something about the new models token usage propensity despite this being a sample of 1.

Fable 5.1 27 input, 65,927 output

Opus 5.5 27 input, 128,000 output (128k thinking tokens) - incomplete

[1] https://tools.simonwillison.net/markdown-svg-renderer?url=ht...