HydraFusion picks a workflow, not just a model, a Copilot CLI explainer says

An explainer describes Project HydraFusion as a research preview in GitHub Copilot CLI. Users select it once, the author says, and it chooses among three approaches: a single model pass, a draft checked against a quality bar, or a draft–critique–revise cycle. In the checked-draft approach, an efficient model goes first, and a quality gate either accepts the result or escalates to a stronger model. The write-up says users pay for that more expensive pass only when the first attempt falls short of the quality bar.